# End of tank dump experiment (now with results)



## coil1002 (Jun 18, 2011)

I never have understood how this can happen. Would the needle valve not prevent this ?


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## btimmer92 (Mar 12, 2011)

IF the end of tank dump happens, it is because of the regulator. The needle valve will NOT prevent it whatsoever. That is a fact, because it does not regulate pressure. If pressure increases, the flow will always increase too. A good needle valve will hold a constant flow AS LONG AS the pressure also remains constant. Does that make sense?

And I am very interested to see the results of this. I traditionally thought only dual stage regs could completely be safe against EOTD, but I along with many others may be wrong. 

Has anyone out there ever run a tank bone dry with a single stage regulator without problems?

And maknwar, I would think using a 10lb for this test might be expensive and take a very long time, lol. Idk if using a paintball tank with adapter would be a better idea or not.


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## maknwar (Aug 10, 2008)

I think im going to use an ideal 52-1-12 for this experiment. Its the most precise needle valve i have right now.


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## mott (Nov 23, 2006)

My ma957 will eotd every time, today as amater of fact my psi went from 900 to 750 or so then the working pressure shot to 35 normaly set at 20. If I would have left it alone it surely gas out all of my fish. Its happened before that's why I always check my tank nightly.


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## coil1002 (Jun 18, 2011)

btimmer92 said:


> IF the end of tank dump happens, it is because of the regulator. The needle valve will NOT prevent it whatsoever. That is a fact, because it does not regulate pressure. If pressure increases, the flow will always increase too. A good needle valve will hold a constant flow AS LONG AS the pressure also remains constant. Does that make sense?
> 
> And I am very interested to see the results of this. I traditionally thought only dual stage regs could completely be safe against EOTD, but I along with many others may be wrong.
> 
> ...


That makes since more pressure on the needle valve higher the bubble rate


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## CL (Mar 13, 2008)

I think of it like how balloons are really hard to inflate at first, but once you've stretched them past their initial size (the size where they look like a lightbulb) they're easy to inflate, except a cylinder would be in reverse as you take gas out. The gas comes out slowly at first, but once it gets to the end of the tank the last bit of liquid CO2 turns into gas and the remaining gas pushes out very fast.


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## maknwar (Aug 10, 2008)

Im assuming thats a Milwaukee setup. So it can be said that Milwaukee regulators do experience eotd. I want to find out if a high quality pressure regulator will experience the same.


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## coil1002 (Jun 18, 2011)

So whens a good pressure to replace the tank to avoid this or should I be weighing the tank ?


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## numbah84 (Jun 28, 2011)

Are there different brands of single stage regulators? MYbe try a top of the line regulator compared to cheap generic one that.... Just a suggestion


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## maknwar (Aug 10, 2008)

I have seen gauges with 500 psi and lower being in the red. I have a tank right now at 500psi so ill report that in my findings as well.

Btimmer, my 10lb tank is at a point where i think it would be a good point to start. High enough pressure to be considered ok for use on an aquarium but i wont have to wait too long. Ill probably have the bubble count high.


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## maknwar (Aug 10, 2008)

numbah84 said:


> Are there different brands of single stage regulators? MYbe try a top of the line regulator compared to cheap generic one that.... Just a suggestion


I want to try a victor or concoa. They make single and dual stage regulators. Victor is one of the most recognized regulator brands and they do not make bad products. If eotd occurs on a victor, I would be surprised if it didnt happen on all single stages.


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## kevmo911 (Sep 24, 2010)

I make no predictions. However, I will say that I've seen a number of people claim that they've had ETOD's using Milwaukees or other low-grade single stage regulators (Aquatek or Azoo, for example). If I had to guess, I'd bet on a MA957 having an EOTD.

But how will you determine this? What if it happens while you're gone for the day? Do you have fauna you're willing to sacrifice in the tank?

And I agree that the quality of the needle valve will have no effect.


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## maknwar (Aug 10, 2008)

kevmo911 said:


> I make no predictions. However, I will say that I've seen a number of people claim that they've had ETOD's using Milwaukees or other low-grade single stage regulators (Aquatek or Azoo, for example). If I had to guess, I'd bet on a MA957 having an EOTD.
> 
> But how will you determine this? What if it happens while you're gone for the day? Do you have fauna you're willing to sacrifice in the tank?
> 
> And I agree that the quality of the needle valve will have no effect.


I was just going to monitor the pressure of the tank daily. Every night, take readings. The pressure should be lowering at a constant rate, and if the tank pressure drops really fast towards the end we have eotd right?

I also just want to point out to everyone that this experiment in no way will be super comprehensive. I think there are too many factors to cover everything right now. Im hoping this might just allow someone else to try something also. The same experiment with a different needle valve, working pressure, etc.


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## kevmo911 (Sep 24, 2010)

Well, the pressure remains constant for 95% of the life of the cylinder. Having no personal experience regarding EOTD, I can't say for certain, but if I had to guess, I'd say that it doesn't seem realistic that the pressure would have a steady decline all of a sudden, given a constant pressure for months, despite losing most of the cylinder's liquid volume. If I were to run the experiment, I would do as you're doing, without any expectations, but put a much hated single fish in the tank (probably a male betta in my case), and see if he lives.


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## maknwar (Aug 10, 2008)

Wow, seems we have a betta hater here, lol.



Are you saying you do or dont think the pressure will drop rapidly when towards the end of co2 volume?

Also, i do think that the needle valve plays a role in eotd. The pressure wont go past what the needle valve is set at on a quality needle valve.


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## mordalphus (Jun 23, 2010)

male betta would just start sucking oxygen at the surface  Use a non-labyrinth fish! I gassed a bunch of shrimp and endlers with EOTD on an azoo single stage before I had it hooked up to a pH controller. The male betta was fine though, hah.


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## BoxxerBoyDrew (Oct 16, 2005)

I have NOT had a eotd happen to me before. And my Regulator is one I got from a online Beer making store. It is a Beverage Factory.com regulator, and I am assuming it is a single stage. It has what looks like a pressure relief valve on the back of it, and a raised female threaded area directly in the center of the back of the Gage. 

Up until last week I have been running a "ice maker" type needle valve on it for YEARS with NO eotd, and I usually wait till the tank is almost completely empty to go swap it out! 

SO I don't know if I have just been extremely lucky or what, but I am now running a Clippard Solenoid valve, a NV-55 Needle valve, a JBJ bubble counter off of the needle valve with a brass check valve between them. I bought it from btimmer92, and it is a heck of a lot better than the ice maker valve and running Co2 24-7!! But I PREY I don't have a eotd now with the better equipment!!!:eek5:

I am going to be checking back often to see what your findings are! 

Thanks for posting about Your Experiment!!!
Drew


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## oldpunk78 (Nov 1, 2008)

You can do a mini test just by turning off the cylinder and opening up the needle valve a bit to speed things up. Most of the (quality) single stage regs I've tried this on only rise about 2-3 psi @ a 30psi working pressure. That's not really enough to drastically change a bubble count. I guess it would make a bigger difference at a lower working pressure.


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## Bettatail (Feb 12, 2009)

oldpunk78 said:


> You can do a mini test just by turning off the cylinder and opening up the needle valve a bit to speed things up. Most of the (quality) single stage regs I've tried this on only rise about 2-3 psi @ a 30psi working pressure. That's not really enough to drastically change a bubble count. I guess it would make a bigger difference at a lower working pressure.


agree.

EOTD is a loose term.

all single stage regulator have *OUTPUT PRESSURE RISE*, when the input pressure drop.
only when the output pressure rise cause large amount of the co2 injection, it is end of tank dump.
a large co2 container with dropping pressure, the volume inside the container still a large amount, so EOTD may happen. There are more factors to put into account of EOTD, when the output pressure is set on the low, the increase(output pressure rise) will cause more co2 injection because the flow volume increase VS original low output pressure setting flow volume is bigger than flow volume increase VS original high output pressure setting flow volume.
so set the output pressure psi higher will prevent EOTD, since the OUTPUT PRESSURE RISE is a fairly a small number compare to the original high pressure output setting.


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## Bettatail (Feb 12, 2009)

to observe the *output pressure rise*:

really simple, on a single stage regulator, set your output pressure at any number with normal input pressure, then turn off the co2 tank.
open the air valve(needle valve), let it release co2 really fast, you will see with the pressure dropping on the HP gauge, there is a slightly rise on the LP gauge.


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## Bettatail (Feb 12, 2009)

a quality single stage regulator only have 0.1 or less psi output pressure rise for every 100 psi input pressure decrease.

that is one of the reason EOTD is not common.


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## dmxsoulja3 (Dec 22, 2010)

I have an Aquatek regulator, not high end by any means, I run it down to zero psi and have never gassed anything, I've watched it as it goes down and never have had an excess amount of C02 released, though before I had a different diffuser it would get the working pressure just high enough to pop the diffuser off a because it was glass and slimy.


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## oldpunk78 (Nov 1, 2008)

A wise man once told me that the end of tank dump is kinda like the jackolope of the hobby. You really only see it happen with old outdated regulator designs like that of the jbj and Milwaukee.


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## trixella (Jan 24, 2011)

mott said:


> My ma957 will eotd every time, today as amater of fact my psi went from 900 to 750 or so then the working pressure shot to 35 normaly set at 20. If I would have left it alone it surely gas out all of my fish. Its happened before that's why I always check my tank nightly.





kevmo911 said:


> I make no predictions. However, I will say that I've seen a number of people claim that they've had ETOD's using Milwaukees or other low-grade single stage regulators (Aquatek or Azoo, for example). If I had to guess, I'd bet on a MA957 having an EOTD.
> 
> But how will you determine this? What if it happens while you're gone for the day? Do you have fauna you're willing to sacrifice in the tank?
> 
> And I agree that the quality of the needle valve will have no effect.


Oh no! Now I'm stressing! I stupidly bought a MA957 from my lfs a few months ago, now to find out that I have a high risk of gassing my fauna... add insult to injury, I paid my lfs $100 more for the piece of [email protected] than what I would have paid online. :icon_frow:icon_frow:icon_frow


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## Bahugo (Apr 18, 2011)

trixella said:


> Oh no! Now I'm stressing! I stupidly bought a MA957 from my lfs a few months ago, now to find out that I have a high risk of gassing my fauna... add insult to injury, I paid my lfs $100 more for the piece of [email protected] than what I would have paid online. :icon_frow:icon_frow:icon_frow


I have the regulator running two tanks with a splitter, 2 bubble counters, 2 needle valves and couldn't be happier. 

If people keep an eye on the tank, and fill it before it completely empties (weigh it), everybody can be EOTD free. 

Just my 2c, yes it can be an inconvenience, but people (like me) who saved a bunch of money on a single stage "bad" regulator compared to regulators people use, should be willing to take the extra 5 min every few weeks to weigh their tank. I understand my regulator can out gas my tank if i ignore it and let it run dry, but taking the 5 min to prevent it is priceless (however sometimes i wish I could secretly off all my fish cause they are physco's :icon_evil).


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## Seattle_Aquarist (Jun 15, 2008)

Hi makenwar,



> Has anyone out there ever run a tank bone dry with a single stage regulator without problems?


Over 3 years ago I purchased a used a Norgren R84-200-MNLA regulator. It actually is designed for carbonated beverages. I used it on a 5# CO2 tank for two years and for this last year on a 15# tank. I have allowed both CO2 tanks to run until empty and have never experienced an EOTD. I use Ideal 52-1-12 needle valves in my manifold.


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## trixella (Jan 24, 2011)

Bahugo said:


> I have the regulator running two tanks with a splitter, 2 bubble counters, 2 needle valves and couldn't be happier.
> 
> If people keep an eye on the tank, and fill it before it completely empties (weigh it), everybody can be EOTD free.
> 
> Just my 2c, yes it can be an inconvenience, but people (like me) who saved a bunch of money on a single stage "bad" regulator compared to regulators people use, should be willing to take the extra 5 min every few weeks to weigh their tank. I understand my regulator can out gas my tank if i ignore it and let it run dry, but taking the 5 min to prevent it is priceless (however sometimes i wish I could secretly off all my fish cause they are physco's :icon_evil).


Have you ever let it run down all the way or are you just on top of the weighing? Also, what weight do I need to be looking for on my five pound canister?


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## Bahugo (Apr 18, 2011)

trixella said:


> Have you ever let it run down all the way or are you just on top of the weighing? Also, what weight do I need to be looking for on my five pound canister?


Too answer you're question, and disperse the rumor about *Ma957 Co2 Regulator Milwaukee:
*My tank literally 15~ min ago ran out. As I said earlier I am using the Ma957 to supply two tanks (with a splitter using 2 stock needle valves and bubble counters), a 56g tank and a 20 gallon shrimp tank. Both tanks are running at roughly 30ppm, so if their was an EOTD it would have been noticeable by how the fish reacted, and especially with the shrimp if their was a gas off I would have been a sad camper (I have 30+ cherry shrimp, 30+ CRS (several of them berried), 8-10 CBS, 6 sunkist shrimp, 4 baby tylo snails growing out, countless ramhorn snails, countless MTS, and 3 otos) . Every shrimp (and snail) and every single fish are completely fine, not one acted funny, swam around like they were trying to get o2, or any of the other signs of dangerous co2 levels. I honestly wouldn't have known it ran out unless I saw the bubbles stop out of my diffusers. I have accidentily reajusted my 56g so the bbs was way to high and I saw the fish change over the course of an hour and i had none of those symptoms. 

I was paranoid because everywhere I see people talking about my regulator, everybody is complaining about how it gasses their fish and constantly has issues etc. Even with the tank running completely dry I still have no flaws with the setup for 100$. You have to keep in mind this is one of the cheapest setups, meaning more people use it and for the 1 complaint there is probably 100 satisfied customers, not to mention for every complaint half of them are probably consumer malfunctions or mishandling. My only "complaint" if their was any would be the needle valve being super sensitive at first. 


Just my .02.


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## btimmer92 (Mar 12, 2011)

I wonder if some people who don't experience EOTD may have a very small leak in their system that is unnoticeable at low psi, but when psi shoots up the leak increases dramatically. It may act as a pressure relief valve. Many people would be surprised to know that they have a small leak, and most systems can develop a leak once their pressure reaches a certain level. Just a thought.


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## maknwar (Aug 10, 2008)

Bahugo said:


> Too answer you're question, and disperse the rumor about *Ma957 Co2 Regulator Milwaukee:
> *My tank literally 15~ min ago ran out. As I said earlier I am using the Ma957 to supply two tanks (with a splitter using 2 stock needle valves and bubble counters), a 56g tank and a 20 gallon shrimp tank. Both tanks are running at roughly 30ppm, so if their was an EOTD it would have been noticeable by how the fish reacted, and especially with the shrimp if their was a gas off I would have been a sad camper (I have 30+ cherry shrimp, 30+ CRS (several of them berried), 8-10 CBS, 6 sunkist shrimp, 4 baby tylo snails growing out, countless ramhorn snails, countless MTS, and 3 otos) . Every shrimp (and snail) and every single fish are completely fine, not one acted funny, swam around like they were trying to get o2, or any of the other signs of dangerous co2 levels. I honestly wouldn't have known it ran out unless I saw the bubbles stop out of my diffusers. I have accidentily reajusted my 56g so the bbs was way to high and I saw the fish change over the course of an hour and i had none of those symptoms.
> 
> I was paranoid because everywhere I see people talking about my regulator, everybody is complaining about how it gasses their fish and constantly has issues etc. Even with the tank running completely dry I still have no flaws with the setup for 100$. You have to keep in mind this is one of the cheapest setups, meaning more people use it and for the 1 complaint there is probably 100 satisfied customers, not to mention for every complaint half of them are probably consumer malfunctions or mishandling. My only "complaint" if their was any would be the needle valve being super sensitive at first.
> ...


Thats great that your setup works great but would you have a different view if you had a malfunctioning unit? Would you just say, i got a lemon and get the same setup over again? I hear that people very satisfied with their Milwaukee setups but i hear just as many that have problems. Also when buying these setups, most people havent tried a custom setup or used high quality parts and can not compare the two. I have used a Milwaukee regulator and can safely say i will never buy another. The quality for the money is way too low.


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## audioaficionado (Apr 19, 2011)

I just went with the dual stage regulator concept in first place. If you build your own or buy a kit from the guys here who build 'em starting at less than $200, how much money do you save if you buy the single stage kits from dealers?

I can still gas my fish, but I'll have to blame my ignorance or foolishness and not my equipment.


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## maknwar (Aug 10, 2008)

I picked up a concoa 400 series single stage i will be using. I am actually going to use a swagelok O series needle valve too. The O series is a little less precise than the ideals which will allow me to rule out needle valves in eotd.


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## trixella (Jan 24, 2011)

audioaficionado said:


> I just went with the dual stage regulator concept in first place. If you build your own or buy a kit from the guys here who build 'em starting at less than $200, how much money do you save if you buy the single stage kits from dealers?
> 
> I can still gas my fish, but I'll have to blame my ignorance or foolishness and not my equipment.


I paid $180 for my MA957 so it sounds like for that price I could have actually gotten a more reliable regulator.


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## Bahugo (Apr 18, 2011)

maknwar said:


> I hear that people very satisfied with their Milwaukee setups but i hear just as many that have problems.


I don't see that many complaints. I see alot of people say "Man, I wish I got a different regulator" after reading posts like this, but are completely satisfied with what they have. Is it the best regulator out there? by no means, but it gets a horrible rep by people who have had issues in the past. I am not coming at you, sorry if it seems that way. The whole time I have had this regulator I have seen threads where people will state "I have heard a bunch of horror stories about this regulator" and this and that. I have looked online and only find a handful of people who have legitimate complaints, alot of it is second hand "My buddy had one and it killed his fish so I got a dual stage regulator". 

I'm sorry, but 90% of the people I see complain about single stage regulator's are complaining about the "what if" or the "I heard from some other site that this happened" where there are plenty of people who have them that don't say anything that are completely satisfied. 

Also, a huge consideration that people forget. For a tank to EOTD the realistic chance of the extra co2 to be absorbed into the water column effecting the fish are very low. glass diffusers will just blow bigger bubbles, inline diffusers will "burp" same with having the co2 injected into the canister filter, etc and it getting lost to the atmosphere. 




audioaficionado said:


> I just went with the dual stage regulator concept in first place. If you build your own or buy a kit from the guys here who build 'em starting at less than $200, how much money do you save if you buy the single stage kits from dealers?
> 
> I can still gas my fish, but I'll have to blame my ignorance or foolishness and not my equipment.


I paid 108$ for mine with tax. 

My closing thoughts, I am not arguing that a single stage is as good as a dual stage. I do feel like people overstretch how horrible a single stage is though. If I could do it over again, would I spend the extra money upfront for the piece of mind? I would be lying if I said I wouldn't, but it wouldn't be for any ill effects towards the single stage setup, it would be because everywhere I turn there is people saying "dual stage is so much better because it won't kill your fish" or "My buddy had a single stage and it killed his fish". I'm satisfied as is though for now, and 108$ for a setup too two tanks is hard to beat. If i upgraded in the future, I would still use my Milwaukee for other tanks and not worry about it.


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## btimmer92 (Mar 12, 2011)

trixella said:


> Oh no! Now I'm stressing! I stupidly bought a MA957 from my lfs a few months ago, now to find out that I have a high risk of gassing my fauna... add insult to injury, I paid my lfs $100 more for the piece of [email protected] than what I would have paid online. :icon_frow:icon_frow:icon_frow





trixella said:


> I paid $180 for my MA957 so it sounds like for that price I could have actually gotten a more reliable regulator.


Take it back, I hope you kept the receipt. I don't care what they say. Tell them You will never come to their shop ever again, and that you will stand outside and tell everyone that they charged twice what it cost online, and that you would give them bad publicity to everyone.


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## audioaficionado (Apr 19, 2011)

The main point was do your homework in advance. Understand how they work and the pros and cons of each system. Then get the best system you can afford with your best informed decision. I'm running DIY yeastie-beastie CO2 still as I can't swing the cost of the 20# CO2 tank yet, but I've gotten the rest of it ready to build when I do. A single stage regulator would be fine, especially if you've already purchased one. If you haven't made the plunge yet, seriously consider a quality dual stage system also with quality post body parts like the solenoid, needle and check valves.

Just don't let marketing hype swing your decisions. Research, research & research some more before you make the plunge. Part of the research is what kind of plants in your planted tank you really want. You don't really need CO2 for any kind of low tech tank and DIY CO2 is fine for most medium tech tanks with slower growing plants too.


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## Jim Miller (Dec 24, 2002)

If you go through the math you'll find that at the point at which all the liquid CO2 is gone there is 16.4% of the total mass of CO2 remaining from the initial fill in a purely gaseous state.

That is the point at which the gauge will start its decline from the whatever nominal room temp pressure it normally shows. Note that these gauges are neither accurate or particularly sensitive, their purpose is to give a general indication of what is going on.

A couple of examples: I just filled my 24oz PB tank at Dick's Sporting Goods here in Baltimore county for $3.99 plus tax. If I had refilled as soon as the tank started downward and was fastidious about checking the gauge I would have wasted 16% of $4 or $0.64. I doubt that any aquarist would lose sleep over $0.64 every month or so needed to refill the tank.

I expect my 20lb tank to last more than a year on my 90g. It cost $27 to fill. Refilling as soon the gauge moved would result in wasting $4.32 on an annual basis. Again, not a material amount.

So my recommendation is if you see the needle move downward and it's not due to a major swing in room temp downward then make a note to get the cylinder refilled as soon as convenient.

Jim


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## HD Blazingwolf (May 12, 2011)

i have a smith regulator, my tank is almost out and no fish, ill chime in on this when my tank runs out


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## maknwar (Aug 10, 2008)

HD Blazingwolf said:


> i have a smith regulator, my tank is almost out and no fish, ill chime in on this when my tank runs out


Awesome. Im guessing thats a gla regulator?


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## mott (Nov 23, 2006)

Jim Miller said:


> If you go through the math you'll find that at the point at which all the liquid CO2 is gone there is 16.4% of the total mass of CO2 remaining from the initial fill in a purely gaseous state.
> 
> That is the point at which the gauge will start its decline from the whatever nominal room temp pressure it normally shows. Note that these gauges are neither accurate or particularly sensitive, their purpose is to give a general indication of what is going on.
> 
> ...


This is what I usually do, as soon as pressure starts to drop I adjust the working pressure for a day or two until I can get it refilled.
If you are like me and check your tank daily it's not that big of a deal, the ma957 is not the best reg by far but its not the worst either.


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## Hoppy (Dec 24, 2005)

Jim Miller said:


> If you go through the math you'll find that at the point at which all the liquid CO2 is gone there is 16.4% of the total mass of CO2 remaining from the initial fill in a purely gaseous state.
> 
> 
> Jim


That isn't true. The initial amount of CO2 in a 5 pound tank is roughly 5 pounds. When the last of the liquid has changed to gas there is very little mass of CO2 left in the tank, many times less than 16%. I'm too lazy to calculate the remaining mass, but the difference in density between liquid and gas is huge.

EDIT: A very rough look at the properties of CO2 convinces me that I may be wrong - sorry.

EDIT2: CO2 is an interesting gas! Another rough calculation: CO2 gas density at 40 atmospheres, at room temperature, is about .08 gm/ml. CO2 liquid density at room temperature and about 800 psi is about .8 gm/ml, ten times as dense. So, a full tank of CO2 would contain about 10 times as much mass as a full tank of gaseous CO2 would contain. If I didn't make any gross errors, the 16% could be about right, perhaps a bit high.


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## btimmer92 (Mar 12, 2011)

that is true. liquid and solid density are very close, but after boiling, the mass increases dramatically in size. However, I am not saying That I know what the percentage would be.


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## oldpunk78 (Nov 1, 2008)

I'm sorry, but am I one of the few that has a spare tank that runs the tank in use down to zero with my 2-stage before just swapping them out and filling the empty at my leisure?[/thread derail]


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## trixella (Jan 24, 2011)

btimmer92 said:


> Take it back, I hope you kept the receipt. I don't care what they say. Tell them You will never come to their shop ever again, and that you will stand outside and tell everyone that they charged twice what it cost online, and that you would give them bad publicity to everyone.


I bought it several months ago so taking it back probably isn't a possibility, especially since this lfs won't take back anything even if it was recently purchased. Other than this sucky reg, I really like this particular store, heads and tails above the other lfs in Austin so I'd be lying if I told them I would not do business with them ever again or give them bad publicity. If my fish end up dying from eotd then maybe I'll be singing a different tune. 



Jim Miller said:


> If you go through the math you'll find that at the point at which all the liquid CO2 is gone there is 16.4% of the total mass of CO2 remaining from the initial fill in a purely gaseous state.
> 
> That is the point at which the gauge will start its decline from the whatever nominal room temp pressure it normally shows. Note that these gauges are neither accurate or particularly sensitive, their purpose is to give a general indication of what is going on.
> 
> ...


This is exactly what I was planning on doing. I don't care about wasting a few bucks if it means that I'll prevent my fauna from dying.


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## Jim Miller (Dec 24, 2002)

If I get time in the next few days I'll post the math.

Jim


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## audioaficionado (Apr 19, 2011)

oldpunk78 said:


> I'm sorry, but am I one of the few that has a spare tank that runs the tank in use down to zero with my 2-stage before just swapping them out and filling the empty at my leisure?[/thread derail]


That's my plan too once I get the initial 20# tank going. Plenty of time to find a backup on Craig's list.


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## oldpunk78 (Nov 1, 2008)

medford.... you're in the same boat I'm in - lol


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## bsmith (Jan 8, 2007)

I'm confused as to why this experiment is being done and how you will actually prove that an EOTD has occurred. 

A single stage regulator by design with EOTD 100% of the time without fail because it has no fail safe (second stage) to keep the gas flowing at the set amount. It can not stop EOTD no matter if its a cheap Milwaukee or some $500 single stage regulator. 

Think of it like this, a single stage regulator is nothing more then a fancy needle valve with a pressure gauge on it. It takes a high pressure gas to a much lower pressure just as a needle valve takes that lower pressure gas to a very low pressure/bubble count. 

Neither one can protect against a post regulator/needle valve flow irregularity because all they do is regulate/control flow based on a given input pressure. With the single stage regulator your output (to the needle valve) raises because the input pressure (co2 tank to the regulator) drops so much that the control orifice inside the unit was simply not designed to function at these lower pressures and fails. When this happens your output/working pressure sky rockets. With a needle valve all your doing is reducing the pressure even more to a level that you can actually see via bubble rate. 

So say you have a working pressure (output from regulator) set at 15psi and your needle valve is set at 4bps. When the EOTD occurs your working pressure can skyrocket to 90psi or higher and since the needle valve only can control its output related to a specific input pressure that 4bps jumps up to 24bps and gassing your tank.


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## maknwar (Aug 10, 2008)

bsmith said:


> I'm confused as to why this experiment is being done and how you will actually prove that an EOTD has occurred.
> 
> A single stage regulator by design with EOTD 100% of the time without fail because it has no fail safe (second stage) to keep the gas flowing at the set amount. It can not stop EOTD no matter if its a cheap Milwaukee or some $500 single stage regulator.
> 
> ...


Im doing the experiment because of what you just said. All single stage regulators will experience eotd. 

I think your wrong and i want to prive it. Ok i have really no idea what will happen when i do it but i want to see for myself.

Im going to monitor the gauges and bubble count daily. When the tank pressure gets lower, im going to try to keep more readings until its empty. Ill track gauge readings, track bubble counts, and ph levels in my aquarium. That should give some idea of whats happening.


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## snafu (Oct 9, 2004)

i can only speak from anecdotal experience, but i've run single stage regulators for many years. never once have i gassed my fish with an eotd. i use all reactors, which i suppose are more prone to gassing than a diffuser. with all the single stage regulators out there, i would imagine we should be hearing about another gassing on a daily basis and we don't. i've been running my milwaukee reg till the bottle is empty for close to 7 years.


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## bsmith (Jan 8, 2007)

Yes but once you realize that a single stage regulator can not stop an EOTD because it was not designed to and that was the reason that dual stage regulators were made it becomes an exercise in futility. Your doing an experiment that the result/answer is already known.

I'm not telling you not to or that I myself dont like testing things but just that you shouldn't devote a ton of time or money to do this.


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## Hoppy (Dec 24, 2005)

bsmith said:


> Yes but once you realize that a single stage regulator can not stop an EOTD because it was not designed to and that was the reason that dual stage regulators were made it becomes an exercise in futility. Your doing an experiment that the result/answer is already known.
> 
> I'm not telling you not to or that I myself dont like testing things but just that you shouldn't devote a ton of time or money to do this.


You have the operation of a regulator wrong. A regulator could be viewed as a variable needle valve, where the valve opening is regulated by the output pressure - low output pressure makes the valve open up a bit, while high output pressure makes the valve close down. The diaphragm in the regulator is the sensor for the output pressure. If the regulator is designed well, and made well, it should be capable of keeping the output pressure from rising much with lower input pressure. I suspect the Milwaukee regulators are not designed that well, and/or made that well.

Two stage regulators make it much easier for the regulator to maintain a constant pressure, by keeping the inlet pressure to the second stage from varying as much. They are inherently better able to keep the output pressure constant under all input conditions.

I still have no idea whether or not all Milwaukee regulators have a problem in keeping the output pressure from rising excessively with lower input pressure, or whether it is variations in quality of the regulators that causes some Milwaukee regulators to have that problem. And, I have no idea whether or not all cheap one stage regulators have the same problem. But, I do know that the Milwaukee regulator I had did have that problem.

This experiment, if done well, should add more to our knowledge.


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## bsmith (Jan 8, 2007)

Hoppy said:


> You have the operation of a regulator wrong. A regulator could be viewed as a variable needle valve, where the valve opening is regulated by the output pressure - low output pressure makes the valve open up a bit, while high output pressure makes the valve close down. The diaphragm in the regulator is the sensor for the output pressure. If the regulator is designed well, and made well, it should be capable of keeping the output pressure from rising much with lower input pressure. I suspect the Milwaukee regulators are not designed that well, and/or made that well.
> 
> Two stage regulators make it much easier for the regulator to maintain a constant pressure, by keeping the inlet pressure to the second stage from varying as much. They are inherently better able to keep the output pressure constant under all input conditions.
> 
> ...


Thanks for the elaboration Hoppy, I knew it was something like that.


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## maknwar (Aug 10, 2008)

Hoppy said:


> This experiment, if done well, should add more to our knowledge.


Care to chime in how you would do it? Im kinda just going to document what is going on with pressure.


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## btimmer92 (Mar 12, 2011)

good description hoppy, a regulator is indeed a variable needle valve. The pressure acts on the diaphragm which is being acted on in the other direction by the spring, which is adjusted by the knob. the higher pressure coming in, the more that needle valve closes, so then the flow going into the low pressure chamber is slowed down, enough to be lower than the flow going out of the end of the system. This will keep the low pressure chamber from taking in too much air at a time, so that the amount of air in the chamber stays low enough to have a certain low pressure. if the output is blocked (like when the solenoid is off) then the pressure acts on the diaphragm enough to fully close the "needle valve", so that no more air comes into the low pressure chamber, and the amount of air trapped in is giving the specified pressure.


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## Hoppy (Dec 24, 2005)

"End of tank dump" is really not a good name for the problem. As I see it, the problem is simple - the regulator output pressure varies inversely with the input pressure. As long as there is any liquid CO2 in the tank, the inlet pressure remains constant, but once the tank contains only gaseous CO2, that pressure drops as CO2 is used. If the outlet pressure rise due to the drop in inlet pressure is too great, the bubble rate will go from a safe level to an unsafe level.

I think a good test is to let the inlet pressure drop, and record the inlet pressure vs the output pressure. We already know that the bubble rate will be proportional to the output pressure, so that doesn't need to be recorded, but can be if you wish.

If your CO2 tank is out of liquid CO2, just record the data about every 2-4 hours until the tank is empty. Then, the most important part: post that data here.


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## milesm (Apr 4, 2006)

i have an azoo regulator. have been using it since late 06. i've gone through 4 refills of my 5lb tank. for the first 3, i just refilled them when the high gauge showed about 250 to avoid eotd. this last time, i waited until it drained to 0. no eotd. in fact, i had to turn up the needle valve considerably to keep up the bubble count.


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## bsmith (Jan 8, 2007)

milesm said:


> i have an azoo regulator. have been using it since late 06. i've gone through 4 refills of my 5lb tank. for the first 3, i just refilled them when the high gauge showed about 250 to avoid eotd. this last time, i waited until it drained to 0. no eotd. in fact, i had to turn up the needle valve considerably to keep up the bubble count.


But I doubt that you watched the tank/Bubble Counter 24/7 as soon as the tank pressure started dropping to see if it jumped at all over the entire period. And of course if your running 200psi instead of 800psi you would need to turn up the BC to compensate.


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## milesm (Apr 4, 2006)

bsmith said:


> But I doubt that you watched the tank/Bubble Counter 24/7 as soon as the tank pressure started dropping to see if it jumped at all over the entire period. And of course if your running 200psi instead of 800psi you would need to turn up the BC to compensate.


yes, you are correct that i didn't watch it 24/7. i will add, however, that my fish weren't showing any signs of distress. 

is it correct to assume that one does not need to turn up the needle valve as the tank gets to 200psi using a dual stage regulator?


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## bsmith (Jan 8, 2007)

If your tank pressure drops by 4x's the amount it is normally at it seems pretty logical that you would have to increase the amount the needle valve allows past by 4x's as well?


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## milesm (Apr 4, 2006)

bsmith said:


> If your tank pressure drops by 4x's the amount it is normally at it seems pretty logical that you would have to increase the amount the needle valve allows past by 4x's as well?


cool. so i get the same performance from my cheapie single stage reg as a dual stage reg.


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## Hoppy (Dec 24, 2005)

bsmith said:


> If your tank pressure drops by 4x's the amount it is normally at it seems pretty logical that you would have to increase the amount the needle valve allows past by 4x's as well?


How is that logical? A regulator maintains the same output pressure, as the input pressure varies, either up or down. It is only the output pressure that determines the bubble rate with a fixed needle valve position. If the tank pressure, the inlet pressure to the regulator, drops by a factor of 4, a good regulator continues to maintain the output pressure constant.


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## bsmith (Jan 8, 2007)

I have never used a SSR so I'm used to my DSR where I can maintain the same bubble rate with a bottle pressure of 900psi or 50psi. What seems logical to me with a SSR is that since it cannot keep a constant output pressue if the bottle pressure drops that you would have to take that pressure drop into account by adjusting your needle valve to keep the bubble count up.


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## milesm (Apr 4, 2006)

bsmith said:


> I have never used a SSR so I'm used to my DSR where I can maintain the same bubble rate with a bottle pressure of 900psi or 50psi. What seems logical to me with a SSR is that since it cannot keep a constant output pressue if the bottle pressure drops that you would have to take that pressure drop into account by adjusting your needle valve to keep the bubble count up.


i guess that's what i wanted to know when i posted in response to your reply, "is it correct to assume that one does not need to turn up the needle valve as the tank gets to 200psi _using a dual stage regulator_?" (italics added). well, at least i don't get an eotd.


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## bsmith (Jan 8, 2007)

milesm said:


> i guess that's what i wanted to know when i posted in response to your reply, "is it correct to assume that one does not need to turn up the needle valve as the tank gets to 200psi _using a dual stage regulator_?" (italics added). well, at least i don't get an eotd.


Yep, that is one of the nice things about a DSR. Bo matter what the bottle pressure is the working pressure you set will remain constant thereby leaving your bubble rate constant aswell. This touches on another point that relates to this nice feature. Sometimes we forget to turn the working pressure all the way down when we take off the bottle to refill it. Then when we hook up the new one and crack the bottle open this puts quite a lot of pressure on the internal diaphragms in the regulator. With a SSR this often times destroys it rendering it useless. With a DSR this cannot happen and no damage will result.


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## milesm (Apr 4, 2006)

bsmith said:


> ...Then when we hook up the new one and crack the bottle open this puts quite a lot of pressure on the internal diaphragms in the regulator. With a SSR this often times destroys it rendering it useless...


the working pressure on the azoo is set at 30-35 psi. is that too high? do repeated refills raise the risk or weaken the diaphragms?


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## bsmith (Jan 8, 2007)

Well if they come from the factory set like that then perhaps the azoo innerds are a bit more beefy than milwaukee. I would try to open the bottle as gradually as possible.


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## calfish64 (Jul 25, 2008)

Is it possible to put a pressure relief valve (say, 30psi) on the output before needle valve to avoid this problem?


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## DerangedCorgi (Oct 15, 2010)

calfish64 said:


> Is it possible to put a pressure relief valve (say, 30psi) on the output before needle valve to avoid this problem?


That should technically work, I mean I don't really see why it wouldn't. :v


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## bsmith (Jan 8, 2007)

You could but I would like to see one and what something like that would cost. 

When the big debate over DSR v SSR first came up there were some members claiming that all you needed was a quality needle valve and you would be safe. As I understood the principle behind a needle valve (can only control flow of a gas in relation to a specific input pressure) I knew this was malarkey. So I actually sent an email to both Swagelok and Ideal explaining the debate and from both of them I received an email reply stating that what I was saying was correct and that no matter how much/how high quality the NV was it could not by design negate an EOTD. I even got a call from a Swagelok district sales rep and he told me about a system that they had to use in conjunction with one of their SSR that was basically a pressure relief valve that would divert the excess pressure flow back through the regulator recycling the extra gas. Then I learned that the system was ~$400 and got the sales man to say that if you had a dual stage regulator there would be no need for the pressure relief flow diverting system! 

You see sometimes I may come off as argumentative but it is only for the reason of getting and all of the myriad myths/folk lore/witch craft that have been in the hobby for many times longer then I have been in it.


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## btimmer92 (Mar 12, 2011)

bsmith said:


> I have never used a SSR so I'm used to my DSR where I can maintain the same bubble rate with a bottle pressure of 900psi or 50psi. What seems logical to me with a SSR is that since it cannot keep a constant output pressue if the bottle pressure drops that you would have to take that pressure drop into account by adjusting your needle valve to keep the bubble count up.


The problem that can happen with a single stage is that as the tank pressure decreases, the working pressure INCREASES. That is the whole reasoning behind the EOTD. You have it backwards.


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## maknwar (Aug 10, 2008)

So here is my new SSR, a Concoa 400 series. Its about the same size as a milwuakee. You guys jealous?


I'm monitoring the regulator right now, so I'll post some results shortly.


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## btimmer92 (Mar 12, 2011)

maknwar said:


> So here is my new SSR, a Concoa 400 series. Its about the same size as a milwuakee. You guys jealous?
> 
> 
> I'm monitoring the regulator right now, so I'll post some results shortly.


Yah but i bet it is heavier than a milwaukee  I also bet it holds a steadier pressure during EOT


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## maknwar (Aug 10, 2008)

actually is not heavier. Thats why this is my new favorite single stage regulator.


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## Hoppy (Dec 24, 2005)

bsmith said:


> I have never used a SSR so I'm used to my DSR where I can maintain the same bubble rate with a bottle pressure of 900psi or 50psi. What seems logical to me with a SSR is that since it cannot keep a constant output pressue if the bottle pressure drops that you would have to take that pressure drop into account by adjusting your needle valve to keep the bubble count up.


That sounds logical, but the reality is the opposite. As the bottle pressure drops, the regulator outlet pressure rises, so you would need to adjust the needle valve to keep the bubble count down. Failure to do so can gas the fish.

This is true for at least one Milwaukee regulator, the one I had.

EDIT: ninja'd by Bill


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## bsmith (Jan 8, 2007)

milesm said:


> i guess that's what i wanted to know when i posted in response to your reply, "is it correct to assume that one does not need to turn up the needle valve as the tank gets to 200psi _using a dual stage regulator_?" (italics added). well, at least i don't get an eotd.





btimmer92 said:


> The problem that can happen with a single stage is that as the tank pressure decreases, the working pressure INCREASES. That is the whole reasoning behind the EOTD. You have it backwards.


You see this is where it gets tricky and is where the source off all this conjecture comes from IMO. I don't believe that an EOTD happens everytime a SSR experiences a pressure drop from the bottle. 

Your statement would be correct if EOTD happened 100% of the time, bottle pressure drops- SSR fails to work properly and causes the output of regulator to go up-bubble rate increases = EOTD

In a normal circumstance, bottle pressure drops-output of regulator drops-bubble rate drops-you counteract this by opening up the NV and your bubble rate is back to normal for a short period of time.

You see what I'm saying here?


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## Hoppy (Dec 24, 2005)

bsmith said:


> You see this is where it gets tricky and is where the source off all this conjecture comes from IMO. I don't believe that an EOTD happens everytime a SSR experiences a pressure drop from the bottle.
> 
> Your statement would be correct if EOTD happened 100% of the time, bottle pressure drops- SSR fails to work properly and causes the output of regulator to go up-bubble rate increases = EOTD
> 
> ...


What you are saying is very easy to understand, but still incorrect. I don't believe any regulator lets the outlet pressure drop as the inlet pressure drops, until the inlet pressure gets lower than the regulator setting. That is the whole point of a regulator - to keep the same outlet pressure no matter what the inlet pressure is. And, good regulators do that very well.


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## bsmith (Jan 8, 2007)

So are you saying that EOTD happens everytime a SSR runs out of liquid co2?


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## maknwar (Aug 10, 2008)

im uploading everything now, ive got some really interesting results.


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## Jim Miller (Dec 24, 2002)

A 1/8" NPT pressure relief valve is pretty inexpensive costing about $5 in single quantity from McMaster Carr. However if you're running 10-15psi and your bubble rate set to yield 30ppm CO2 the 50psi relief valve will still allow the bubble rate to triple or quadruple the CO2 amount before it activates.

Oops...

Jim


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## btimmer92 (Mar 12, 2011)

unless you have your working pressure just below your relief valve rating


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## Jim Miller (Dec 24, 2002)

The problem with picking a relief valve for a product is that some folks use diffusers that require 30psi while others use a much lower pressure. The lower pressure is often used to make the adjustment of the overly sensitive needle valve somewhat easier.

I use a NV55 and find it a real PITA to adjust. A very small turn, probably about a degree, moves the bubble rate from around 1bps to well over 5bps.

But if you're building your own and pick a pressure you can buy a suitable relief valve. Hard to do when making a product serving a variety of customers.

Jim


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## Hoppy (Dec 24, 2005)

bsmith said:


> So are you saying that EOTD happens everytime a SSR runs out of liquid co2?


No, I'm saying any regulator which allows the output pressure to rise as the input pressure drops will cause a higher bubble rate to occur, and that will kill the fish if you run your CO2 at near the maximum the fish can live with. I know the Milwaukee regulator I had did that, every single time. I don't know how many Milwaukee regulators do the same thing nor do I know if any other manufacturers regulator does it. But, *I suspect* that all cheap regulators do it.

There is never a "end of tank dump". Dumping isn't the problem. Increased bubble rate is.


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## hbosman (Oct 5, 2006)

Hoppy said:


> No, I'm saying any regulator which allows the output pressure to rise as the input pressure drops will cause a higher bubble rate to occur, and that will kill the fish if you run your CO2 at near the maximum the fish can live with. I know the Milwaukee regulator I had did that, every single time. I don't know how many Milwaukee regulators do the same thing nor do I know if any other manufacturers regulator does it. But, *I suspect* that all cheap regulators do it.
> 
> There is never a "end of tank dump". Dumping isn't the problem. Increased bubble rate is.


Before I went to Victor VTS 250 (dual stage) regulators, I had a Red Sea Paintball single stage regulator and a Total Beverages Single Stage regulator. Both SS regs would gradually increase output pressure as input pressure decreased. I had to reduce the bubble rate daily as the 20 OZ paintball cylinder emptied.

I would guess that if I had been using a 5 lb cylinder like I do now, that the increase in output pressure might not have been noticed daily ie...the increase would have been more gradual. Anyway, the rise in pressure could have been avoided if I would have swapped cylinders sooner.


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## maknwar (Aug 10, 2008)

Pressure of tank was 500+ psi. Working pressure was at 10 psi. Bubble counter was set at around 1 bps.









http://img192.imageshack.us/img192/9910/file12604.mp4










http://img64.imageshack.us/img64/9488/file12604x.mp4










http://img843.imageshack.us/img843/9910/file12604.mp4










http://img59.imageshack.us/img59/9910/file12604.mp4










http://img16.imageshack.us/img16/6149/file12604a.mp4










http://img16.imageshack.us/img16/6149/file12604a.mp4


When the tank was empty, and working pressure is below 5 psi.
http://img268.imageshack.us/img268/9910/file12604.mp4


When the tank pressure lowered to around 400 psi, the bubble count raised to about 2 bps. As the tank gradually ran out, the bps continused to come out at about 2 bps. The working pressure also raised to about 15 PSI at 400 psi.


When the tank had no more pressure, the bps slowed down. I would not call this a EOTD at all. The bps did double, so that would explain the EOTD rumors. The lower quality regulators, might have different results that would allow triple or more bps when the tank drops below 500 psi resulting in what many think as a true EOTD.


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## audioaficionado (Apr 19, 2011)

Perhaps EOTD isn't a precise enough term for gassing fish due to SS regulator's failure to fully control the output/working pressure throughout the full life of the CO2 tank.

Any increase in CO2 output pressure that's not automatically controlled by the regulator is *BAD* and can easily result in fauna death.

What's the correct term or a better term for this phenomenon?


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## HD Blazingwolf (May 12, 2011)

my tank emptied last night, ambient temp was 76, pressure in tank below 500 increased output pressure from 30 psi to 31 psi on my smith regulatoor from GLA. bps increase wasnt noticeable unless timed oover a 100 second interval. bps went fromm 1.7/s to 1.82/s drop checker had no change in 2 hours, ph change was negligable. plannts and fauna didnt mind. i run my setup between 45 and 50 ppm c02 daily. hach c02 test kit gave me my usual variable of 48 ppm.


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## audioaficionado (Apr 19, 2011)

So it's obvious that all SS regs are not equal quality. Some are acceptable in regulating the end of tank liquid to all gas phase and some are not.

Now is this brand or model specific or just a poor unit to unit quality control issue?

A lot of system builders of any equipment source the raw parts on specs and/or price points. So a branded system might use different components for their same model system depending on their supplier and pricing issues over a period of time.


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## Hoppy (Dec 24, 2005)

What brand regulator was this test done with? I can see one problem that might affect the results: that regulator seems to be a higher pressure output regulator than is usually used with a CO2 system, so it might be less able to regulate down around 15-20 psi.


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## oldpunk78 (Nov 1, 2008)

^ That looks like a concoa 400 series 100 psi regulator. There isn't much difference from the 25-50-100 psi models. What I've found makes the biggest difference is the working pressure you are using. 20-30 psi results in a smaller pressure rise as the tank empties.


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## btimmer92 (Mar 12, 2011)

Maybe its not an EOTD, but a doubling of the bubble count could definitely cause fish death if you have your co2 level just low enough for your fish to survive. I guess a lot of ppl don't have their CO2 level that high, which is why their fish don't die, but a lot of ppl including myself, need to have the CO2 at the upper limit to grow great plants. So, even the highest quality SSR does not allow you to keep your co2 level at the upper limit safely. I think there is something to be said for that. You don't have to call it an EOTD if you don't want, but I call it a gassing of fish, which is the whole point. So if you have a single stage regulator, basically, you can't keep your co2 level high enough to grow great plants in a high tech tank while keeping your fish safe.


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## btimmer92 (Mar 12, 2011)

That regulator is a concoa regulator. I am under the impression that those are very high quality regulators.


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## oldpunk78 (Nov 1, 2008)

How long did the faster bubble count last for? I mean, it takes a while for the extra gas to reach critical levels - it doesn't happen right away. ...and then the flow stops.


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## oldpunk78 (Nov 1, 2008)

btimmer92 said:


> So if you have a single stage regulator, basically, you can't keep your co2 level high enough to grow great plants in a high tech tank while keeping your fish safe.


You might hear quite an argument on that one.


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## btimmer92 (Mar 12, 2011)

Jim Miller said:


> I use a NV55 and find it a real PITA to adjust. A very small turn, probably *about a degree*, moves the bubble rate *from around 1bps to well over 5bps.*
> 
> 
> Jim


Are you kidding?.... I use about 30 psi, a nv-55, and an atomic diffuser and it probably takes a 30 degree turn of the knob to go from 3 bps to 4 bps.


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## btimmer92 (Mar 12, 2011)

oldpunk78 said:


> You might hear quite an argument on that one.


Oh I am aware old plunk lol I have already had a few ppl go crazy at me for suggesting that, DON'T CARE, I still feel that way. Bash away, SSR users


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## Jim Miller (Dec 24, 2002)

btimmer92 said:


> Are you kidding?.... I use about 30 psi, a nv-55, and an atomic diffuser and it probably takes a 30 degree turn of the knob to go from 3 bps to 4 bps.


No I'm not kidding. Perhaps they shipping me a bad valve or not the one I ordered. But it really sux.

What pressure are you running?

Jim


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## btimmer92 (Mar 12, 2011)

30 psi, what about you?


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## sajata (Aug 21, 2009)

Getting to this a little late but i have several of thr GLA ultimate regulator setups on 20# 5# and 2.5# tanks. I always run the tanks dry. I have never had a problem. I use both the atomic in tank and in line running 35psi working preassure and a ceramic at 15psi. No dumps... 


Sent from my DROIDX


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## Jim Miller (Dec 24, 2002)

Same. I'm taking the CO2 apart in a day or so to move stuff around. I'll take a closer look at the NV55 to see what the heck is wrong with it.

Jim


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## HD Blazingwolf (May 12, 2011)

mine is a smith regulator body. specs can be found on green leaf aquariums. i have the ultimate II setup


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## bsmith (Jan 8, 2007)

btimmer92 said:


> Maybe its not an EOTD, but a doubling of the bubble count could definitely cause fish death if you have your co2 level just low enough for your fish to survive. I guess a lot of ppl don't have their CO2 level that high, which is why their fish don't die, but a lot of ppl including myself, need to have the CO2 at the upper limit to grow great plants. So, even the highest quality SSR does not allow you to keep your co2 level at the upper limit safely. I think there is something to be said for that. You don't have to call it an EOTD if you don't want, but I call it a gassing of fish, which is the whole point. So if you have a single stage regulator, basically, you can't keep your co2 level high enough to grow great plants in a high tech tank while keeping your fish safe.


You took the words right out of my mouth. I am one of those people that have my BC set so that any increase without me knowing could have the potential to gas my fish relatively quickly.


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## Hoppy (Dec 24, 2005)

Some time back, maybe a year or so, someone on here contacted a regulator company and they informed him that all single stage regulators have a problem holding the pressure setting, without it rising, when the inlet pressure goes down. I had forgotten that. If this is a high quality regulator, and it does look like one, I think it demonstrates that point. But, this one has a gauge that goes from vacuum (-30 inch Hg) to + 200 psi, making it hard to read the difference between 10 and 15 psi, and I suspect making it a regulator that has the problem much worse than if the regulator was a 0-50 psi regulator. I have no proof of that, just speculation.

Those who are conscientious enough to carefully check the pressures on their regulator every single day, probable will never have a problem, even with a Milwaukee regulator. But, people like me who tend to forget to do that, probably should use 2 stage regulators.


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## oldpunk78 (Nov 1, 2008)

Hoppy said:


> Those who are conscientious enough to carefully check the pressures on their regulator every single day, probable will never have a problem, even with a Milwaukee regulator. But, people like me who tend to forget to do that, probably should use 2 stage regulators.


haha - I don't think I've checked mine in month. I just tend to make sure there are still bubbles in fish tank. lol

I wonder if stainless diaphragms work any different compared to neoprene when it comes to a pressure rise at the end.


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## bsmith (Jan 8, 2007)

I know that stainless diaphragms would be much better for people like me that do not turn down the working pressure when swapping to a new tank. I have heard of ppl with cheaper SSR's popping their diaphragm when doing this. On my DSR when I hook up the fresh bottle and crack open the new one the bottle pressure pops up to 850-950 (depending on bottle temp) and the working pressure pops up to 30psi with no drama.


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## oldpunk78 (Nov 1, 2008)

Just for reference, you're not supposed to do that ^ lol


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## bsmith (Jan 8, 2007)

oldpunk78 said:


> Just for reference, you're not supposed to do that ^ lol


Of course not but who an remember everything all the time. :hihi:


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## 150EH (Dec 6, 2004)

I'm using and old Dupla 400 regulator that is much more primative than the regulators you guys are using, it only has a low pressure gauge but a very good needle valve, so it works well. When my 5# (7.25 lbs) is full the gauge reads a constant 65 lbs of pressure and when the needle drops into the red at 60 lbs of pressure I know there is only a week to 10 days of gas left. I have weight the tank as soon as this drop occurs and it weighs 8.5 lbs, so I have a pound and a quarter of gas in the tank. If I wait it will dump with no results to my fish that I have noticed but I make sure to get it filled a couple of days after the drop so I don't run out of gas. My bottle lasts about 40 days and I run my bubble count between 5 to 6 bps or better, I am thinking of a second CO2 system on this tank so I can easily achieve my CO2 levels with 2 reactors and 2 bottles at 3 bps would last twice as long. My filling station does not carry 10# bottles and the 20's are a little too tall but only $2 more to fill, it's a shame they won't fit under my stand. I also like the idea of the Carbon Doser regulator at Aquarium Products even if it clicks a little, it will only be for 8 hours during the day but the bubble rate is fixed and it electronic so it can't dump.


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## Hoppy (Dec 24, 2005)

A quality regulator is not harmed by a sudden application of pressure. When I was working many years ago I once used a regulator on an air system that was hit with 2000 psi air from a solenoid valve, with the outlet pressure set to 1500 psi. It worked perfectly every time. It had remotely mounted pressure gages, each with some damping, and those were never harmed either. The Milwaukee regulator is the only one I know of that will destroy the output pressure gauge when you hit it with a surge of input pressure, but I don't think the diaphragm is ever damaged.


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## maknwar (Aug 10, 2008)

Hoppy, the regulator is a concoa. Probably just as good as a victor, harris or any other brand of regulator. I do have a victor single stage that i could hook up, but i think the results are going to be the same.

Also regarding the working pressure gauge if 200. It was a lot harder to get a pic of it, but the gauge was not as hard to read as it looks. I wish i had a 0-60 gauge but i didnt. 

If any one wants to document their end of tank experience, please feel free to do so in this thread.


I think that if your pumping so much co2 into your tank that it's going to kill your fish if the bps doubles, you might want to cut back the light. Then you can cut back the co2. Any disagreements?


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## btimmer92 (Mar 12, 2011)

maknwar said:


> I think that if your pumping so much co2 into your tank that it's going to kill your fish if the bps doubles, you might want to cut back the light. Then you can cut back the co2. Any disagreements


Yes. When I had algae problems, everyone told me to reduce light, AND to increase CO2 as much as I could without the fish dying. It worked.

Furthermore, Tom Barr recommends not using a bubble counter or a drop checker and just increase the flow slowly until the fish show stress, and then turns it back down to the last level he had it at safely.


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## maknwar (Aug 10, 2008)

Ok so the solution for people with ss regs?


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## btimmer92 (Mar 12, 2011)

use low light, and only grow low light plants, hope not to get algae.


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## bsmith (Jan 8, 2007)

maknwar said:


> Ok so the solution for people with ss regs?


If they keep co2 levels just below the level that can harm fish I really don't think there is any answer. I would normally say just buy a DSR but that won't really help the issue here. 

Also I would concur that a Concoa regulator is just as good if not better then a Victor. I have both and know that this has nothing to so with what's inside but my Concoa feels more substantial than my Victor does. This also varys greatly between the models too.


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## Hoppy (Dec 24, 2005)

The solution is very simple: just establish the habit of checking your regulator every morning or every evening, looking to be sure the two gauges read correctly. This will let you identify when the tank pressure starts to drop, and you can adjust the regulator every day to keep the bubble rate constant. That is just part of the price of using a single stage regulator - but not a high price at all.


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## DerangedCorgi (Oct 15, 2010)

Hoppy said:


> The solution is very simple: just establish the habit of checking your regulator every morning or every evening, looking to be sure the two gauges read correctly. This will let you identify when the tank pressure starts to drop, and you can adjust the regulator every day to keep the bubble rate constant. That is just part of the price of using a single stage regulator - but not a high price at all.


Seriously, it only takes a glance to see if anything's wrong.


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## 150EH (Dec 6, 2004)

I don't use a solenoid but I turn up the bubble count to 5-6 bps second every morn about an hour or more before the lights come on and then reduce the count every evening to 1 bubble every 5 to 10 seconds after lights out. It's not really any trouble because I have to come feed the fish every morning anyway.


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## James4226c (Dec 8, 2009)

Hoppy said:


> The solution is very simple: just establish the habit of checking your regulator every morning or every evening, looking to be sure the two gauges read correctly. This will let you identify when the tank pressure starts to drop, and you can adjust the regulator every day to keep the bubble rate constant. That is just part of the price of using a single stage regulator - but not a high price at all.


I have an old azoo reg and no bubble counter and I agree with you 100% I have at least 1 minute everyday to admire my aquarium so during that time I can spare a few seconds to open my cabinet door to read 2 gauges.

Even if I don't look at my regulator gauges my fish and plants can tell me if there is any thing wrong.


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## DerangedCorgi (Oct 15, 2010)

James4226c said:


> I have an old azoo reg and no bubble counter and I agree with you 100% I have at least 1 minute everyday to admire my aquarium so during that time I can spare a few seconds to open my cabinet door to read 2 gauges.
> 
> Even if I don't look at my regulator gauges my fish and plants can tell me if there is any thing wrong.


I should set up a live stream and view it on my phone! On second thought...


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## audioaficionado (Apr 19, 2011)

My Victor VTS450D DSR is such a heavy weight regulator that it could supply an entire LFS. This thing is huge compared to many of the sleek TPT SnS offerings of late.


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## Mxx (Dec 29, 2010)

Inspired by this thread, I let my CO2 tank and single stage regulator 'dump'. Pressure is down to zero now, and I had no problems, my drop checker never changed from its usual green to yellow and I never saw any signs of distress in the fish. I suppose that I don't keep my CO2 at max levels in the first place, and I do have an HOB filter which creates quite a bit of surface agitation and therefore off-gassing I'm sure, but no problems in any case. 

The regulator I bought off Ebay, and I added a second in-line needle valve as I was finding the regulator's one to be a bit too touchy, although a second needle valve shouldn't make any difference in terms of EOTD. This is the regulator and the Ebay description - Aquamedic CO2 - pressure regulator regular - 104, apparently. 
"The Aqua Medic CO2 Regulator is a precision German regulation valve for standard CO2 cylinders. High quality nickel plated brass housing operates at a fixed working pressure of 22 PSI and includes two pressure gauges to monitor both the cylinder and working pressures. For exacting bubble counts in critical applications like Calciumreactors and CO2 Reactors, the needle valve allows fine tuning and adjustment."


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## maknwar (Aug 10, 2008)

Mxx said:


> Inspired by this thread, I let my CO2 tank and single stage regulator 'dump'. Pressure is down to zero now, and I had no problems, my drop checker never changed from its usual green to yellow and I never saw any signs of distress in the fish. I suppose that I don't keep my CO2 at max levels in the first place, and I do have an HOB filter which creates quite a bit of surface agitation and therefore off-gassing I'm sure, but no problems in any case.
> 
> The regulator I bought off Ebay, and I added a second in-line needle valve as I was finding the regulator's one to be a bit too touchy, although a second needle valve shouldn't make any difference in terms of EOTD. This is the regulator and the Ebay description - Aquamedic CO2 - pressure regulator regular - 104, apparently.
> "The Aqua Medic CO2 Regulator is a precision German regulation valve for standard CO2 cylinders. High quality nickel plated brass housing operates at a fixed working pressure of 22 PSI and includes two pressure gauges to monitor both the cylinder and working pressures. For exacting bubble counts in critical applications like Calciumreactors and CO2 Reactors, the needle valve allows fine tuning and adjustment."


What is your approximate bubble rate that you run?


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## plantbrain (Dec 15, 2003)

For the record, I have NEVER advocated gassing your fish to maximize CO2 or cure algae! I have suggested slow methodical adjust till the algae abates and most importantly, the plants grow. FYI


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## Mxx (Dec 29, 2010)

maknwar said:


> What is your approximate bubble rate that you run?


I appreciate that some run their co2 as high as they can, which puts them on the verge of danger should anything shift for any reason, but I don't use co2 that aggressively. I had just adjusted the bubble rate upwards until it was almost 2 bubble per second before the drop checker registered as green, albeit on a small tank. And regardless of whether the CO2 tank was full or almost empty, the drop checker registered the same green colour so I didn't see any end of tank dump whatsoever.


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## Optix (May 31, 2011)

so thank you for the experiment maknwar

...still use my cheapo Milwaukee SSR proudly. Only had 1 accident (only gassed fish when I first got it due to over excitement) but never experienced EOTD 

but long story short....take a 2 seconds to look at my drop checker and see if its royal blue/forest green/lime green/neon yellow and 3 seconds to adjust bubble rate accordingly

CHECK!


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## Sharkfood (May 2, 2010)

I've run my Milwaukee down to maybe 300 PSI. 

I think to get an EOTD you'd have to ignore your CO2 setup for weeks on end, and then be very unlucky as well.

You have days, if not weeks to refill your tank when you see the pressure start to decrease.


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## Optix (May 31, 2011)

Ive run my milwaukee to E...but Ive never just let it go for days/weeks at a time without looking at my drop checker...


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## bsmith (Jan 8, 2007)

I think its worth posting again that EOTD only happens when a person keeps their co2 levels on the verge of gassing their fish. The tank dumps EVERY SINGLE TIME with a SSR but weather or not that kills your fish depends on where you keep your co2 levels. Simple as that.


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## btimmer92 (Mar 12, 2011)

That may be true, however, the term "on the verge" is very subjective and cannot really be rationalized. Also, it doesn't really dump, as in emptying all at once, it just constantly increases pressure until it runs out. But as you mentioned, every SS reg will have this occurrence every single time. That is just a fact, and the companies that make industrial (quality) regulators will tell you this.


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## bsmith (Jan 8, 2007)

btimmer92 said:


> That may be true, however, the term "on the verge" is very subjective and cannot really be rationalized. Also, it doesn't really dump, as in emptying all at once, it just constantly increases pressure until it runs out. But as you mentioned, every SS reg will have this occurrence every single time. That is just a fact, and the companies that make industrial (quality) regulators will tell you this.


Its not really that subjective in practice. If you increase the amount to co2 you are injecting in small amounts over a large time frame until you see stress in your fauna then back it down a bit and run this bubble count, its pretty concrete. 

If you have a SSR and run out of liquid co2 and aren't going to be coming home for the few hours after that you will have deaths.


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## HypnoticAquatic (Feb 17, 2010)

i would like to add what ive noticed when i ran a higher psi i noticed a much smaller increase in pressure vs a lower psi which had a higher increase due to the % ex say 20 psi goes to 25 a 5 psi increase has resulted in a 25% increase, now if i was at 50 psi an it went up to 55 thats a 10% increase so that has a big factor to me that people dont really think about.


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