# Any good DIY CO2 from ebay?



## Darkblade48 (Jan 4, 2008)

Depending on your aquarium size, it might be difficult to overdose on DIY CO2; in general, it does not generate a lot of CO2.

DIY CO2 is cheap, but a hassle to maintain, and can be expensive (both time-wise and economically) in the long run.

Yeast with sugar is the most common setup. Using carbonated liquids would be much more difficult to control.

Regarding diffusion methods, a glass diffuser would work well, but not all work with DIY CO2 (DIY CO2 cannot always generate the pressure required to overcome the resistance).


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## greaser84 (Feb 2, 2014)

Glass diffusers and DIY co2 don't work well, not enough pressure. DIY co2 is very inconsistent so counting bubbles doesn't work, you'll find that when the yeast mix gets warm the bubbles come out faster and slow down when the yeast mix gets colder. If you want to diffuse the bubbles put the tubing directly under a powerhead so they get sucked up, then chopped up and tossed across the tank. I did DIY co2 for a long time and got sick of using my coffee sugar!:icon_smil I will say that diy co2 makes some killer prison moonshine!


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## Beer (Feb 1, 2012)

The fluval ceramic diffuser has worked well for me. It doesn't look as nice as a glass diffuser, but it is small, unobtrusive, and can be tucked out of the way.

I use 20 oz soda bottles for tanks around 5gal and 16oz or 12oz for tanks around a gallon.
Surface are effects off-gassing rate. It takes less than 10 minutes to rinse the bottle, add some warm water, sugar, and molasses (not totally necessary), shake it to dissolve everything, let the foam settle for a couple minutes, add yeast, and hook it back up.
I get two and a half to three weeks in the winter, about two, or just under, in the summer. If you do bi-weekly water changes, swap it then and call it good.

People over think it and over complicate it. Keep it quick and simple or go with a pressurized system.


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## EvilFish (Oct 15, 2013)

Seems that citric acid and baking soda creates much more pressure than yeast based co2.


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## Darkblade48 (Jan 4, 2008)

EvilFish said:


> Seems that citric acid and baking soda creates much more pressure than yeast based co2.


Yes, this is definitely the case, but you will need some method to store all that pressure. Do you trust a pop bottle to do that?

The problem with the acid/base reaction is that it will produce all the CO2, "all at once" (not technically true, but relative to yeast).


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## EvilFish (Oct 15, 2013)

> Do you trust a pop bottle to do that?


They have over-pressure valve (ebay items 171183500365 or 151168533645).
First one looks much better.



> The problem with the acid/base reaction is that it will produce all the CO2


How long I can use it? I heard that up to 8 weeks.

Thanks


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## Darkblade48 (Jan 4, 2008)

EvilFish said:


> They have over-pressure valve (ebay items 171183500365 or 151168533645).
> First one looks much better.
> 
> 
> ...


I still think it is over engineering what should be a simple system. I very much doubt that an acid/base reaction will last more than a day, much less 8 weeks.

Mix some vinegar and some baking soda together. See if it continues to fizz after a few hours (much less the 8 weeks you claimed).


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## EvilFish (Oct 15, 2013)

> system. I very much doubt that an acid/base reaction will last more than a day


Quick research on google and found this:
-Yes this system works but u put citric acid in one and bicarb in other bottle. Lasts about a month

-It has definite potential. Now I have it sorted it's puttering along at about 40 bubbles/min in my 30L without needing fiddling with.

-Early days but it seems more controllable and consistent than the traditional yeast system.

I ordered one with bubble counter


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## TekWarren (Oct 6, 2013)

I'm running DIY yeast on my 40breeder and get a ton of pearling. It's no more hassle than learning/experimenting about any other aspect of this hobby. Key things making sure you have no leaks, regular alternating solution changes so the fluctuation is less, and HOW you diffuse it. Diffusion is a big deal and it needs to be efficient in order to get any real benefit.

That said, pressurized offers stability in the amount you are delivering which is also a big deal.


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## charlie 1 (Oct 22, 2006)

Darkblade48 said:


> I still think it is over engineering what should be a simple system. I very much doubt that an acid/base reaction will last more than a day, much less 8 weeks.
> 
> Mix some vinegar and some baking soda together. See if it continues to fizz after a few hours (much less the 8 weeks you claimed).


The way it works , is the citric acid is not drawn into the bottle with the base until the pressure drops in the base bottle, via negative pressure a bit of acid is drawn into the base bottle.
There is also a control valve to regulate your delivery rate.
I saw a demo on it twice & I`m convinced it trumps the sugar & yeast system, also as mentioned there is a safety pressure valve.
Regards


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## EvilFish (Oct 15, 2013)

But what is better?
1. Acid citric and soda
2. Vinegar and soda
3. Yeast and sugar
4. Jello and Yeast

Thanks


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## greaser84 (Feb 2, 2014)

TekWarren said:


> I'm running DIY yeast on my 40breeder and get a ton of pearling. It's no more hassle than learning/experimenting about any other aspect of this hobby. Key things making sure you have no leaks, regular alternating solution changes so the fluctuation is less, and HOW you diffuse it. Diffusion is a big deal and it needs to be efficient in order to get any real benefit.
> 
> That said, pressurized offers stability in the amount you are delivering which is also a big deal.


How do you diffuse it? I always just put the tube under a power head. All the other ways I tried failed.


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## Darkblade48 (Jan 4, 2008)

charlie 1 said:


> The way it works , is the citric acid is not drawn into the bottle with the base until the pressure drops in the base bottle, via negative pressure a bit of acid is drawn into the base bottle.
> There is also a control valve to regulate your delivery rate.
> I saw a demo on it twice & I`m convinced it trumps the sugar & yeast system, also as mentioned there is a safety pressure valve.
> Regards


I am confused still how this system works.

It says to fill the bottle with about 400-600 mL of water and 200 grams of citric acid. How is this solution drawn into the sodium bicarbonate bottle? I am not sure, but it appears that the two bottles are connected by tubing through that blue block?

I still think it's over engineering a system. DIY CO2 with yeast and sugar was designed to be easy, and cheap (cost of sugar and yeast, so less than $5). This system looks to be about $55, so it is quite a step up. 

Personally, I would rather save up the money and go for a good pressurized system, but...


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## TekWarren (Oct 6, 2013)

greaser84 said:


> How do you diffuse it? I always just put the tube under a power head. All the other ways I tried failed.



The best way I've found for my setup is using the ista max mix inline with my canister filter. 


Also I agree with dark blade. To the OP, don't waste your money on eBay junk if your going this route. All you need are some 2 liter bottles, good air line tubing, sugar, yeast, and water.


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## EvilFish (Oct 15, 2013)

Can I use solenoid (17$ on ebay) with soda+acid citric?


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## TekWarren (Oct 6, 2013)

I wouldn't. You can shut off pressurized CO2 because it is a liquid contained tank that can hold the pressure. DIY production doesn't stop and the pressure has to go somewhere...


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## EvilFish (Oct 15, 2013)

How much CO2 do I need for 29g low light (almost medium 28PAR)?

10-20ppm is OK?

Can I use this device with yeast/sugar too? (just put the yeast/sugar to 1 bottle or in 2?)

Thanks


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## Darkblade48 (Jan 4, 2008)

The ideal concentration of CO2 to have is 30 ppm. You can probably get by with 10-20 ppm.

You could probably use that device with yeast/sugar too, though again, it's a $55 solution for something that should cost less than $5.


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## EvilFish (Oct 15, 2013)

Darkblade48

Its easy to overdose with DIY CO2?


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## Jubs (Apr 5, 2006)

Darkblade48 said:


> I am confused still how this system works.
> 
> It says to fill the bottle with about 400-600 mL of water and 200 grams of citric acid. How is this solution drawn into the sodium bicarbonate bottle? I am not sure, but it appears that the two bottles are connected by tubing through that blue block?
> 
> ...


I have this system and have been logging progress on my club's mailing list for Gary Lange, I have had it set up for about a month and it is very stable. I had to come up with my own recipe of the mix to make sure it lasted long enough, the recipe I found online wasn't enough to last more than a couple weeks for me (I think a lot of the reason was I used up a lot of the citric acid the first time setting it up).

How it works is the whole system is pressurized (when you set it up) and when the pressure drops (you won't notice the pressure drop) it causes the bottle of citric acid to syphon a couple or less ml's into the sodium bicarbonate solution which causes the pressure to equalize and the remaining citric acid solution syphons back into it's bottle. 

I run this at 1 bubble per second 24/7 and have over 2 weeks on my current mix of solutions and have only used half or less of the citric acid solution up. 

I run pressurized as well but for a diy this is by far the most stable I have found and have used several different yeast methods with great success over the years but this is honestly the best and most stable diy system I have used personally. 

As stated above I would like to put a solenoid on it and it would really be the closest you could get to pressurized for ease of use and stability. This system would be great for people that don't have ready access to co2 refills but want a stable level of co2.

If you shop around on eBay you can find a plastic version that is $35 and has built in tool holders (for tweezers, scissors, ect) and the seller is from the states so you don't have to wait for airmail. I bought mine this way and had it in 2 days.

Here's a quick picture of the system on my 40 breeder tank I have been testing it out on.











TekWarren said:


> I wouldn't. You can shut off pressurized CO2 because it is a liquid contained tank that can hold the pressure. DIY production doesn't stop and the pressure has to go somewhere...


This is true to a point, but the system will not build more pressure until the pressure has dropped within the system. There is also an adjustable safety valve that allows the system to bleed off the excess pressure once it reaches the point you have set on it.

This system is surprisingly pretty idiot proof if you use it as it is intended to be used.


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## cape (Oct 26, 2013)

Hi Jubs, thank you for the great review. Just wondering is there noticeable fluctuation with this system and if you can share your own recipe would be great.


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## Darkblade48 (Jan 4, 2008)

EvilFish said:


> Darkblade48
> 
> Its easy to overdose with DIY CO2?


I'm not sure if this was meant as a question or a statement.

I have not overdosed with DIY CO2 before, when I was using it (for a couple of years). I then go fed up with the hassle of changing the mixture and just went full pressurized and never looked back.


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## Jubs (Apr 5, 2006)

cape said:


> Hi Jubs, thank you for the great review. Just wondering is there noticeable fluctuation with this system and if you can share your own recipe would be great.


You're welcome. 

I have not experienced any fluctuations other than in the first 24 hours after set up. It is good to check the pressure 24 hours after setting it up, I did have my pressure drop a little bit in this period the second time I reset it. 

As for my recipe so far so good but I haven't ran the full cycle on it yet, so take that into consideration as well. The only issue I am considering happening is some form of pressure change when the baking soda side gets almost full from the larger amount of citric acid mix and how or if it will affect the syphoning effect of the system being closer to the top of the bottle. 

The recipe I am currently using is converted so anyone that doesn't have a scale can make it with simple measuring cups. This is roughly double the original I found (and used) on a forum via google searches. 

Bottle A 
1 3/4 cups citric acid powder
5 cups water

Bottle B 
1 1/2 cups baking soda (sodium bicarbonate)
2 cups water


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## burr740 (Feb 19, 2014)

Eh nevermind, think I answered my own question


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## EvilFish (Oct 15, 2013)

24$ for 5lb of citric acid is good price?
Do I need food grade cit. acid?

Baking soda 30$ for 15lb is OK too?


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## TekWarren (Oct 6, 2013)

Darkblade48 said:


> You could probably use that device with yeast/sugar too, though again, it's a $55 solution for something that should cost less than $5.



This should be the main point you take away from this thread...unless you already purchased the device, your throwing money away that could be saved for a pressurized system. There is absolutely no reason to spend $55 on a DIY yeast production system. You can buy a LOT of sugar and yeast for that much money and use pop bottles which you can find for free, air line tubing which might be a couple dollars, and check valves also a couple dollars.

The drop checker on my 40B is light yellow using DIY yeast in 2 liter bottles. Granted I'm running 6 bottles setup in pairs with a check valve. I change 1 pair each week so they are running steady for 3 weeks. I just can't see the reason to spend the money on what is essentially a "holder" for the bottles.


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## EvilFish (Oct 15, 2013)

I bought 2kg of Baking Soda in Walmart for 4$.
5lb acid citric on amazon.ca 24$. I don't know if there is a cheaper acid citric somewhere...

Total cost for charging - 2.58$. That's not expensive, it must provide me a stable CO2. In russian forums many use it with solenoid without any issues. But all cheap solenoids on ebay are for 220-240V...

I found one for 110V, it's *Milwaukee Solenoid Valv*e. 48$


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## cape (Oct 26, 2013)

TekWarren said:


> This should be the main point you take away from this thread...unless you already purchased the device, your throwing money away that could be saved for a pressurized system. There is absolutely no reason to spend $55 on a DIY yeast production system. You can buy a LOT of sugar and yeast for that much money and use pop bottles which you can find for free, air line tubing which might be a couple dollars, and check valves also a couple dollars.
> 
> The drop checker on my 40B is light yellow using DIY yeast in 2 liter bottles. Granted I'm running 6 bottles setup in pairs with a check valve. I change 1 pair each week so they are running steady for 3 weeks. I just can't see the reason to spend the money on what is essentially a "holder" for the bottles.


Yes but that is assuming they are equal. Some users, including poster above claims this system is a lot more stable than the standard yeast system.


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## Jubs (Apr 5, 2006)

cape said:


> Yes but that is assuming they are equal. Some users, including poster above claims this system is a lot more stable than the standard yeast system.


They are no way near equal, other than most use 2 liter bottles and they both produce co2, when properly set up. 

Trust me, I was very skeptical myself and only bought it to test it out, I had no plans on actually liking it. I run pressurized as well and there is no replacement for that, but this is as close as I have found. It is even more stable than the UP Aqua pressurized system, I use to run. I have not had any difference in pressure when the room temp has risen in the past couple weeks of warmer weather, I can't say that about the "cheap" (still more expensive than this system was) UP system or yeast. 

Will I be buying more of these systems? No, not likely because I love the ease of pressurized but it is a great product for people not willing to take the plunge into pressurized and want more out of a DIY system.


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## jeffkrol (Jun 5, 2013)

Jubs said:


> snip


Something tells me you'd need a solenoid between the bottles..


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## EvilFish (Oct 15, 2013)

Hmmm... Nope:


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## jeffkrol (Jun 5, 2013)

EvilFish said:


> Hmmm... Nope:


so if the solenoid gets stuck in the closed position..what happens.......???


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## EvilFish (Oct 15, 2013)

Nothing. 200g of soda and acid citric cannot produce 8kg/cm2 pressure. And safe valve will be released at 4kg/cm2. I guess... 

Sent from my SGH-I337M using Tapatalk


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## jeffkrol (Jun 5, 2013)

EvilFish said:


> Nothing. 200g of soda and acid citric cannot produce 8kg/cm2 pressure. And safe valve will be released at 4kg/cm2. I guess...
> 
> Sent from my SGH-I337M using Tapatalk


I know it is not possible but that is why I suggested a solenoid between the bottles.. Stops the reaction while allowing the pressure built up to vent.. 
When the solenoid opens the reaction would begin again.. I think.. maybe w/ a check valve on the outtake
I'm actually surprised they can hold the 35psi w/ out blowing off the bottles..
but I guess this isn't as much as I think..

anyways just spit balling here for discussion. I'm probably not grasping the whole concept..
As long as releasing the safety is just gas.. really no mess...


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## EvilFish (Oct 15, 2013)

jeffkrol said:


> I know it is not possible but that is why I suggested a solenoid between the bottles.. Stops the reaction while allowing the pressure built up to vent..
> When the solenoid opens the reaction would begin again.. I think.. maybe w/ a check valve on the outtake
> I'm actually surprised they can hold the 35psi w/ out blowing off the bottles..
> but I guess this isn't as much as I think..
> ...


But with the solenoid between the bottles do I need to shake it every day?

I'll verify that with russians guys who use this DIY CO2.


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## Jubs (Apr 5, 2006)

The discussion has continued on my club's list and one of our members is opening a specialty plant shop and some people from the club are buying these directly from him and one of the customers received this from him. This is a direct quote from the manufacturer. 

_1. You will need two 2 liter PET soda bottle, e.g. Coke, Pepsi, etc.
2. Mark these bottles as Bottle A and B.
3. Empty Reagent A (Citric Acide 200 grams) into Bottle A and add
600ml of water. Shake well until everything is dissolved. You will
notice that the water will be colder to touch.
4. Take out one of the DIY CO2 system. There are two areas where you
can screw on the PET bottles. The first one is the one with a
pressure gauge (A) and the second one is the one with the regulator
(B).
5. Screw in Bottle A you made in number 3 into DIY CO2 (A).
6. Empty Reagent B (Baking Soda 200 grams) into Bottle B and add
200ml of water. You do no have to dissolve the contents in Bottle B.
7. Screw in Bottle B into DIY CO2 (B).
8. Close the regulator of the DIY CO2 and make sure it is completely shut off.
9. Squeeze Bottle A until liquid in Bottle A starts to transfer to
Bottle B. You should see reaction that will start producing CO2.
Keep on squeezing Bottle A until bottle is very firm (full of gas) and
you can't squeeze the bottle anymore.
10. Attach CO2 gas tubing to the regulator and to the CO2 diffuser.
Release regulator slowly until you see bubbles coming out of the CO2
diffuser.

Many first time users turn on the regulator too fast resulting to the
citric acid water moving too fast to the baking soda area, thus
reducing the true potential lifetime of the co2 production. The whole
trick here is to trickle drip citric acid into the baking soda bottle.

You don't have to touch anything for the citric acid to flow into the
baking soda. Once reaction started, it will automatically such citric
acid into the baking soda when it is needed. However, it has been
observed that you may need to swirl the bottles once a week to make
sure that fresh baking soda gets exposed to the citric acid.

You should get around 6 weeks at 8 hours a day of CO2 at 1 bubble per
second. Although we can get sometimes up to 8 weeks._

So if you read till the end they state that it should be shut off daily, manually I don't do that currently but will be investing in a solenoid to do it for me lol. 

Like stated above the pressure can not increase with it shut off if it is up to working pressure, the pressure inside of the bottles is what causes the whole thing to work and causes a syphon to build up more pressure when it is needed and only when it is needed, kind of genius once you get how it all works. It's really hard to explain it without seeing it work in person.


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## jeffkrol (Jun 5, 2013)

Still leads to believe a solenoid between the 2 reaction bottles would make it "automated" as in no reaction.. 

Which As I said would have to be in a DIY set up since the "joiner" piece is one piece plastic..



> The whole
> trick here is to trickle drip citric acid into the baking soda bottle.


The only problem w/ the solenoid on the outlet is you will never completely stop the reaction.. since the 2 solutions will always be allowed to mix (albeit very slowly) by natural diffusion. I don't see it as a problem, and breaking the draw between bottles may, in practice, not work i.e it might not restart.
you also have a problem w/ salt/acids attacking the valve.

My Chem is a bit rusty though and it looks like a solenoid on the out is just fine..and much simpler
Not to mention at that rate.. running 24/7 wouldn't kill the fish either (I could be wrong on this though)..just exhaust your ingredients.


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## Jubs (Apr 5, 2006)

jeffkrol said:


> Still leads to believe a solenoid between the 2 reaction bottles would make it "automated" as in no reaction..
> 
> Which As I said would have to be in a DIY set up since the "joiner" piece is one piece plastic..
> 
> ...


That's the thing, when the baking soda side gets 1 ml or 2ml of citric acid it completely backs itself back into the citric acid bottle, the line is completely clear of citric acid it doesn't stay in the line at all. As the pressure drops a tiny bit after a few hours it very slowly refills the line from the citric acid bottle but it doesn't continue to stay in the line on the baking soda bottle. It doesn't syphon the citric acid quickly, it takes hours, but it does retract back into the the citric acid bottle within a second or two (if that long) and then the line remains clear of the citric acid till the syphon starts over again.

Like I said, you'd have to see it in action to really understand how it works.

One thing to remember is this isn't a science class vinegar and baking soda chemical reaction, it is a small little fizzle and its over. This is because of the diluted solutions of acid and alkalinity of the solutions in the bottles. I'm pretty sure if you were to use a raw acid and raw bicarbonate then the whole thing would explode from the violent chemical reaction but this isn't how this works. 

There is also no way to put a solenoid between the bottles as the entry between the bottles is built into rail it is not an airline/co2 tubing. I have seen a couple kits on eBay that include a solenoid with the kit but I bought mine from a stateside seller the others were from Asian sellers and I didn't know at the time how the system truly worked and figured someone was trying to make an extra buck.


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## EvilFish (Oct 15, 2013)

DON'T USE THIS DEVICE!
It always leaks (CO2 leak), pressure jump, needle valve get blocked by acid.
Acid destroy all rubber parts (thats = CO2 leak).

I'll try to use it with sugar+yeast.


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## Darkblade48 (Jan 4, 2008)

Hilde said:


> What is your recipe? Where do you get your citric acid?


Citric acid can normally be found at the pharmacy.


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## EvilFish (Oct 15, 2013)

The problem of this device is evacuation valve, it's always leak.
I blocked this valve and the things goin much better now.


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## Darkblade48 (Jan 4, 2008)

EvilFish said:


> The problem of this device is evacuation valve, it's always leak.
> I blocked this valve and the things goin much better now.


I thought this valve was there to prevent the bottle from exploding in case the CO2 line gets blocked? If so, why would you want to purposely disable a safety feature?


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## Hilde (May 19, 2008)

Darkblade48 said:


> Citric acid can normally be found at the pharmacy.


I don't see it at websites of CVS or Walgreens. I saw it on Walmart website. Found it cheapest at a wine brewing co. One lb $7. Can it be bought cheaper?


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## EvilFish (Oct 15, 2013)

The pressure will never going to 8 (bottle's max). So, you're safe to disable it. It's always leak and cause the pressure up, this increase the bubbles count and can wipe out your fishes. 

So, make sure it's not leak (put the whole system in the water when you charge it) . Also, you can use half of the dose and solenoid (there is not any problem with it). 

If the pressure up without reason it's 100% leak.


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## Hilde (May 19, 2008)

Jubs said:


> The recipe I am currently using is
> Bottle A
> 1 3/4 cups citric acid powder
> 5 cups water
> ...


How long does it last?


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## EvilFish (Oct 15, 2013)

Hilde said:


> Big Fish says, "The solenoid would simply allow co2 pressure


I never had pressure up due to solenoid. Only due to CO2 leaks. I set the pressure to 1, close the valve and wait 3 days. The pressure stay at 1.



> I have read by others like Hoppy that DIY Co2 is not strong enough to kill fish when on 24/7.


Yeast and sugar DIY CO2 yes. But this one is different and can kill the fishes easily if the pressure gonna up to much.



> Some inject it via a powerhead that is on a timer.


I tried ebay's chinese know off diffuser for 5$, it doen't work well. With Fluval's CO2 Diffurer you have much better absorption rate.
But sure, better to inject it via powerhead or filter.


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## Darkblade48 (Jan 4, 2008)

Hilde said:


> I don't see it at websites of CVS or Walgreens. I saw it on Walmart website. Found it cheapest at a wine brewing co. One lb $7. Can it be bought cheaper?


$7 for one pound is reasonably cheap.


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## Hilde (May 19, 2008)

Darkblade48 said:


> $7 for one pound is reasonably cheap.


Calculated need at least 6lb for a year if DIY Co2 last 4 weeks. Baking soda is about the same price. Thus yearly cost $84. Seems cheaper in long run to do pressurized system. Cheap pressurized system is a Fluval66 converted to a Paintball tank.


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## maxham51 (Jul 31, 2014)

Hilde said:


> Calculated need at least 6lb for a year if DIY Co2 last 4 weeks. Baking soda is about the same price. Thus yearly cost $84. Seems cheaper in long run to do pressurized system. Cheap pressurized system is a Fluval66 converted to a Paintball tank.


For less then that I can buy 10 lbs of Citrus acid and Baking soda which will last about 2 1/2 years on a 20 gallon aquarium. The real problem is not the price difference but that you have to readjust the needle valve with each refill. This problem can be solved by inserting a ball valve on a tee just before the needle valve. Cheap solution. This makes the Acid/soda solution almost as good as a pressurized system at a fraction of the cost. With this mod it is better then the cheap pressurized systems like the Fluval 20 or 88, as the bubble count is much more stable.


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## Hilde (May 19, 2008)

maxham51 said:


> For less then that I can buy 10 lbs of Citrus acid and Baking soda which will last about 2 1/2 years on a 20 gallon aquarium.
> 
> You have to readjust the needle valve with each refill. This problem can be solved by inserting a ball valve on a tee just before the needle valve.


Where do you buy the Citrus acid and Baking soda? 

Seems this ball valve here would work.

Is it cheaper than Paintball Co2 system:
Refills $12 a year and Startup $108:
Aquatek Paintball CO2 Regulator $88 on Amazon 
20 oz Paintball Tank $20 on Amazon


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## EvilFish (Oct 15, 2013)

Another problem is that liquid in the bottle transforms to something like jelly and block the CO2. I got the problem very often, when it happens, I need to empty the whole system and clean everything.

Next months I'll buy a real CO2 5LB system.


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## maxham51 (Jul 31, 2014)

EvilFish said:


> I never had pressure up due to solenoid. Only due to CO2 leaks. I set the pressure to 1, close the valve and wait 3 days. The pressure stay at 1.
> 
> 
> Yeast and sugar DIY CO2 yes. But this one is different and can kill the fishes easily if the pressure gonna up to much..


 I don't know why people keep passing the rumor that yeast systems won't kill your fish. This is simply not true, yeast systems can easily kill your fish. The first time I tried a yeast system it started going and looked good. I was getting a bubble about very 9 seconds which is just what I wanted. I woke up the next day to find all my fish dead and it was now going at over 1 bubble per second. I tested the water and found that the ppm of CO2 was over 200. This was just from a 2 liter bottle in a 20 gallon tank.


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## Hilde (May 19, 2008)

maxham51 said:


> For less then that I can buy 10 lbs of Citrus acid and Baking soda which will last about 2 1/2 years on a 20 gallon aquarium. The real problem is that you have to readjust the needle valve with each refill. This problem can be solved by inserting a ball valve on a tee just before the needle valve.


Thanks for the info.

Googling Citris acid 5lbs and Baking soda 5lbs found -Citric Acid USP/Food Grade 5 Lb 14.95 Etsy andBaking Soda 3.68 at Walmart. Total is 18.63. Thus now thinking more strongly about getting the kit. 

So when you refill it you decrease the output with the valve?


EvilFish said:


> Another problem is that liquid in the bottle transforms to something like jelly and block the CO2.


Has anyone besides EvilFish had this problem?


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## Hilde (May 19, 2008)

EvilFish said:


> I never had pressure up due to solenoid. Only due to CO2 leaks. I set the pressure to 1, close the valve and wait 3 days. The pressure stay at 1.


So the safety valve is not necessary?
Where and for how much did you buy the solenoid?
How long have you been using it?
Did you get a different needle valve?

So the *solenoid* turns your CO2 on/off automatically. 
For how long is it off? 
Any problems when it restarts?

Is this the solenoid that you are using


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## EvilFish (Oct 15, 2013)

> So the safety valve is not necessary?


Nope. Just use half of dose (I use 25% of dose acid citric & soda). It's good for 2 weeks and pressure will never up too much.



> Where and for how much did you buy the solenoid?


Everything on eBay (20$ price range) is for 220V. I bought Milwaukee Solenoid Valve 47$. Works well.



> How long have you been using it?


3 months. 



> Did you get a different needle valve?


Maybe I need one, good one. But I won't invest a cent for this system. It works and it's OK. If I need something better, I'll invest 300$ for real CO2 system.



> So the solenoid turns your CO2 on/off automatically.


Yes. But your pressure must be 1. It's much more safe and prevent CO2 leak due to high pressure. 1 is enough even for Fluval CO2 diffuser.



> For how long is it off?


On from 10 to 20h. Off form 20h to 10h 



> Any problems when it restarts?


Nope. But first 3 days check it when it starts, to see if the bubbles rate is the same.



> Is this the solenoid that you are using


Buy a real solenoid, not the Chinese knock-off. 
http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=28113 40$
Same for diffuser, get the good one: Amazon.com : Fluval Ceramic 88g-CO2 Diffuser - 3.1 Ounces : Workplace First Aid Kits : Pet Supplies 5$


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## Hilde (May 19, 2008)

EvilFish said:


> Buy a real solenoid, not the Chinese knock-off.
> http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=28113 40$


 If I did that cost of system would be $93. 

A paintball system will cost $100. 
Aquatek Paintball CO2 Regulator $88 at Amazon
20 oz Paintball Tank $20 at Amazon

Since I use Excel most of the time I will get the cheapest Co2 kit and try running it 24/7. Or I will get a Fluval Co2 system.


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## Hilde (May 19, 2008)

Jubs said:


> I have this system and have been logging progress on my club's mailing list for Gary Lange


I would like to view your progress.


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## EvilFish (Oct 15, 2013)

Fluval CO2 system? To buy a expensive co2 every months? 
You don't need a solenoid for paintball? 
Is not necessarily to run it 24/7, yours plants doesn't need co2 when the light off. 

But I'm agree, better to buy a real co2 system. 300$.


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## Hilde (May 19, 2008)

EvilFish said:


> Fluval CO2 system? To buy a expensive co2 every months?
> You don't need a solenoid for paintball?
> 
> Is not necessarily to run it 24/7, yours plants doesn't need co2 when the light off.
> ...


My main concern is to inject Co2 while I am out of town. 

So if I get the fluval I will just run it for a few weeks.

If I get the citric kit it seems cheaper to just run it 24/7. Then I could diffuse it through a small internal filter set on a timer. Read 1 did this and said the bubbles that came out at night were big and thus would not gas the fish. 

If paintball doesn't have a solenoid then it runs 24/7. I think that would gas the fish.

I can't spend $300 on a true Co2 system so that is out.


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## EvilFish (Oct 15, 2013)

To inject co2 when you're out of town and be safe, you'll need a good equipment with good solenoid and good needle. 

Acid citric system isn't safe, it can leak, jump the pressure and wipe out all your livestock. 

You idea with the timer isn't great. Imagine if it's start to leak. Pressure jump from 1 to 4. When timer is ON, your bubbles rate will be not as you set it, but 5-10 times more... 

You cannot be safe with this kind of systems. Whem I'm out of town for even 1 day I close my co2.

I don't know about this risk for paintball or fluval system. Fluval is expensive to operate.


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## Hilde (May 19, 2008)

EvilFish said:


> Acid citric system isn't safe, it can leak, jump the pressure and wipe out all your livestock.
> 
> You idea with the timer isn't great. Imagine if it's start to leak. Pressure jump from 1 to 4. When timer is ON, your bubbles rate will be not as you set it, but 5-10 times more...


Well I am not to concerned about the livestock. They are all replaceable for a few dollars from Pet Smart. I am more concerned with my plants. That is why I got into this hobby.

The more I think about it I feel safer using the citrus setup. For I am envisioning if something goes wrong with a cheap pressurized tank that there could be an small explosion. For a few had major problems with the aquatec regulator.


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## bigd603 (May 10, 2011)

Hilde said:


> Well I am not to concerned about the livestock. They are all replaceable for a few dollars from Pet Smart. I am more concerned with my plants. That is why I got into this hobby.


Regardless of their cost, they are still living creatures. They have one life, and then they're gone. They did not choose to be fish. I promise you, to them their life is pretty valuable and they would really enjoy staying alive as long as possible.


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## Hilde (May 19, 2008)

bigd603 said:


> Regardless of their cost, they are still living creatures. They have one life, and then they're gone. They did not choose to be fish. I promise you, to them their life is pretty valuable and they would really enjoy staying alive as long as possible.


Well I do what I can to maintain their life. I feed them spectricide food and frozen food, but I am limited financial as to what I can do. 

I have read that others using this system at 1bps run it 24/7 with no problems. That is what I try to do. If I see problems before I go out of town I will turn it off.


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## Hilde (May 19, 2008)

jeffkrol said:


> Something tells me you'd need a solenoid between the bottles..


Here the solenoid is between the bottles.


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## Okedokey (Sep 2, 2014)

My DIY produces heaps of pressure. I run the airline tubing via a check valve and controls to the top of a eheim 2010 which is perfect as I can lay it on its side, provide extra hidden filtration and circulation and the filter 'atomizes' the CO2 into minute bubbles. I have 2 x 2L soda bottles with a cup of sugar, teaspoon of yeast and a teaspoon of bicarbonate in each vessel. Pressure is significant and lasts for weeks. No dramas for me. I also got a DIY solenoid from ebay that turns it off at night.


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## ajwan (Sep 16, 2014)

I'll chime in here. Got the same Ebay unit as Evilfish as shown in the picture in #32.

Mine cost me $50 US. I got 2 kg of baking soda from Walmart for $5, and 3 kg of citric acid from my local soap shop for $15. Total is $70.

I didn't have a clue how this worked, but it does! What happens is that when you squirt the acid side (A) into the NaHCO3 side (B), bubbles will form. B will then pressurize then send CO2 through the line and bubble up in A. The rise in pressure in A will register in the overlying pressure gauge. As CO2 is depleted from the needle valve located at bottle B, the pressure will drop relative to the A bottle. This pressure differential will then cause the citric acid to re enter the line. Given enough time, the citric acid will finally drop into B, restarting the reaction and the whole process starts all over again.

It's not like the acid in A rushes over to B. It's a very slow process and appears to be self regulating. The only thing you have to do is swirl the liquids to ensure the reaction is complete, when it happens.

The instructions say to continue the reaction until the gauge reads 2-3 kg/cm2.

https://www.youtube.com/watch?v=mqMqIdJMRM4

I prefer to leave it at 1.5 kg/cm2 as the needle valve is less fiddly at the lower pressure than the higher pressure. Plus I feel more at ease when the system is at a lower pressure overall.

My only complaint is that the seals in the bottle connectors are not really that great as I got leaks. I replaced them with ordinary garden hose seals and had no further problems.

I've had my unit going on for the last 3 days (on 12 hours, off 12 hours). Given the rate of citric acid depletion, I would estimate 1 - 2 months until I have to dismantle and replenish the system. The pressure really is stable and does not fluctuate. I'd say I have enough NaHCO3 and citric acid to last me at least 1.5-2 years!!!!

Yes there are rubber seals, and they probably do deteriorate given time. I fully expect to replace all rubber seals when the unit needs to be replenished. I think this is a small price to pay for the upkeep of the system. Plus the rubber seals should only cost a few dollars at most at your local Home Depot or other hardware store.

Very satisfied.

Regards.


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## Hilde (May 19, 2008)

ajwan said:


> I'll chime in here. Got the same Ebay unit as Evilfish as shown in the picture in #32.


I am debating weather to get that 1, 501 or 201. For he had a problem with the safety valve. Have you had any problems with the safety valve or pressure changing suddenly?


EvilFish said:


> The problem of this device is evacuation valve, it's always leak.
> I blocked this valve and the things going much better now.


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## ajwan (Sep 16, 2014)

Hilde said:


> I am debating weather to get that 1, 501 or 201. For he had a problem with the safety valve. Have you had any problems with the safety valve or pressure changing suddenly?


None so far. But keep in mind, I keep my pressures at 1.5 kg/cm2 and well below the limit the safety valves opens up (4-5 kg/cm2). 1.5 kg/cm2 is enough to send many many bubbles/s through my single ceramic diffuser. I find the flow easier to adjust at this lower pressure.


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## Hilde (May 19, 2008)

ajwan said:


> I keep my pressures at 1.5 kg/m2 and well below the limit the safety valves opens up (4-5 kg/m2). 1.5 kg/m2 is enough to send many many bubbles/s through my single ceramic diffuser. I find the flow easier to adjust at this lower pressure.


I think I will do that. Also seems the pressure valve unnecessary thus I will get the cheapest 1. 

Seems the main difference between the 501 and 201 is the holder which I can DIY and pressure valve which is unnecessary, and the air stone for bottle A, which I have. 

Am I correct?


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## ajwan (Sep 16, 2014)

I should also mention that I don't run a solenoid. I simply turn on the needle valve 30 mins before the light comes on.

Forgive me, but I'm unfamiliar with the 501 and 201. Could you send a link?


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## Hilde (May 19, 2008)

ajwan said:


> I should also mention that I don't run a solenoid. I simply turn on the needle valve 30 mins before the light comes on.
> 
> Forgive me, but I'm unfamiliar with the 501 and 201. Could you send a link?


The 501 is in post #32 Here is the 201


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## ajwan (Sep 16, 2014)

Hilde said:


> The 501 is in post #32 Here is the 201


Ah yes. Mine came with a "matching" blue bubble counter and some spare washers. I think the bottle washers included with the 501 are useless. Garden hose washers work much better.


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## ajwan (Sep 16, 2014)

Here's my set up:

CO2 Diffuser
















Generator as it appears under my desk.








Not a big fan of the surf shop, but guess the kids need their fun! Could be worse...








Like I said, nothing special it's a 10 gallon. My kids had input so I HAD to put in the surf shop and fake plant! LOL! All other plants are real.


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## Hilde (May 19, 2008)

ajwan said:


> Not a big fan of the surf shop, but guess the kids need their fun!


I think it adorable and fun looking. 

Now I am temped to get the 1 you have. Looks like you have a check valve that I have. Seller said it wouldn't work with the kit. He thinks the kit is no good too, though. Is it like the 1 here? Did you get it with the kit?


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## ajwan (Sep 16, 2014)

Hilde said:


> I think it adorable and fun looking.
> 
> Now I am temped to get the 1 you have. Looks like you have a check valve that I have. Seller said it wouldn't work with the kit. He thinks the kit is no good too, though. Is it like the 1 here? Did you get it with the kit?


The model I got came with the bubble counter which comes with a check valve and seems to work just fine. My diffuser also comes with an integrated check valve (and itself serves as a bubble counter). Actually, now that you mention it, I have a third check valve which is being used as a connector for the tubing (behind the desk and not visible). Thinking about it, I now realize I've got too many check valves! Probably hindering the flow somewhat. I'll probably get rid of the one on top of my generator (the blue one); clearly redundant.

One thing I'll mention is that even at 1.6 kg/cm2, the needle valve is VERY sensitive. However, I'm still able to achieve my desired flow rate. It stays stable throughout the day as the pressure, like mentioned in an earlier post, does not fluctuate.

My tank was planted two weeks ago. Hopefully within a month or two the foreground plants will have formed a nice carpet. The background plants should also grow out and become more dense. The fake plant on the middle fixture is a bit of an eyesore. I'll probably cut that out and tie on some java fern or something.


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## Hilde (May 19, 2008)

ajwan said:


> One thing I'll mention is that even at 1.6 kg/cm2, the needle valve is VERY sensitive. However, I'm still able to achieve my desired flow rate. It stays stable throughout the day as the pressure, like mentioned in an earlier post, does not fluctuate.


I read - You have to readjust the needle valve with each refill. This problem can be solved by inserting a ball valve #50 on a tee just before the needle valve


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## awwyiss (Aug 19, 2014)

Any updates from users of the citric acid system?


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## Psyonix (Jul 15, 2014)

I purchased this set up from Ebay:








Plus, an extra bottle cap from a different seller.

I am not using it with Acid/Baking Soda however, I converted it to Yeast/Sugar. Using (2) 2 Liter bottles for mixture (one bottle changed out every two weeks, alternating bottles), a 20 oz bottle as a gas separator/bubble counter, and a Fluval Ceramic Diffuser in the tank.

It produces a steady stream of CO2 through the diffuser, pressure on the gauge is just below 1000psi all the time (minor fluctuations when I change out the mixture in a bottle) 

My problem with DIY CO2 before was I could never create enough pressure to go through a diffuser without popping a leak somewhere in the setup (usually where the hose enters the bottles). 
This has been awesome for the price (less then 20.00 all in, plus cost of sugar and yeast). I can post pictures of my actual setup later if anyone is curious.


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## awwyiss (Aug 19, 2014)

Oh nice that's the same system I am waiting to arrive. I will be using citric acid method bit would still love photos of your setup. Do you leave it running 24/7?
Thanks!


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## Okedokey (Sep 2, 2014)

I have that system too. 

1000PSI? Do you mean 1 kg/cm2? That is 14PSI.


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## Psyonix (Jul 15, 2014)

awwyiss said:


> Oh nice that's the same system I am waiting to arrive. I will be using citric acid method bit would still love photos of your setup. Do you leave it running 24/7?
> Thanks!


I do leave it running 24/7. I have an air pump that comes on at 'sundown' to help get more oxygen into the water, but the CO2 is such a small amount I don't think it hurts to leave it on 24/7. 



Okedokey said:


> I have that system too.
> 
> 1000PSI? Do you mean 1 kg/cm2? That is 14PSI.


Sorry, it's right below the "1" on the pressure gauge (the green area).


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## Hilde (May 19, 2008)

I have been reading that many leave the Co2 on 24/7. Yet bigd603 gave me a lecture about my plan to do that. Know of a few whom do it with pressurized Co2 too. Seems to depend on the bio-load if proves to be a problem.


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## Hoppy (Dec 24, 2005)

You can leave the CO2 running 24 hours if you are not running near the maximum bubble rate the fish can live with. When you are near the maximum the decrease in how much CO2 is used by the plants at night causes the concentration in the water to increase enough to harm the fish. That's why DIY CO2 can run 24 hours without problems.


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## Okedokey (Sep 2, 2014)

Hoppy said:


> You can leave the CO2 running 24 hours if you are not running near the maximum bubble rate the fish can live with. When you are near the maximum the decrease in how much CO2 is used by the plants at night causes the concentration in the water to increase enough to harm the fish. That's why DIY CO2 can run 24 hours without problems.


I just max it out and when its dark turn the airstone on.


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## brooksie321 (Jul 19, 2014)

Okedokey said:


> I just max it out and when its dark turn the airstone on.


I've been running the fluval mini system at 1 bps 24/7 (trying at least, this system is kind of impossible to maintain consistent bips). DC is lime at the end if day. I kick air stone on at..... well now actually! 9 pm and it runs until 6 am. Betta and rcs couldn't be happier.. wish the dhg would get happy


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## flight50 (Apr 17, 2012)

Plants actually which gears at night and use O2 and not CO2. This is why many people shut it off at night and run air stones to oxygenate the water. The smaller the bioload the more oxygen to go around. With that said. I ran pressurized CO2 24/7 at 25-30ppm without issues a few years back on a 55g moderately plant tank. My reason was to hold a certain ph. Now the real question that I don't know, is how much CO2 hung around in the water after the lights went off after its 12hr cycle.

So if pressurized CO2 can be ran 24/7, diy is a joke and will present no treat at all. I did diy co2 for a year when I first started out in 02' and it wasn't as technical as it is now. I couldn't even remotely tell you how to stop CO2 from a diy setup way back then and I wouldn't worry about trying to stop or regulate it now. If you find yourself needing to regulate the flow, this is when you jump to pressurized.


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## awwyiss (Aug 19, 2014)

For anyone using the citric acid / bi carb soda method:
If you find the pressure rises overnight you need to increase the water in the citric acid bottle for your next mixture.
I changed from 600 to 700mL in just the citric acid bottle and have not had pressure rises over night.
I should say I am using a solenoid to automatically shut off the system over night (between the system and the diffuser)
Hope this helps.


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## Okedokey (Sep 2, 2014)

flight50 said:


> Plants actually which gears at night and use O2 and not CO2. This is why many people shut it off at night and run air stones to oxygenate the water. The smaller the bioload the more oxygen to go around. With that said. I ran pressurized CO2 24/7 at 25-30ppm without issues a few years back on a 55g moderately plant tank. My reason was to hold a certain ph. Now the real question that I don't know, is how much CO2 hung around in the water after the lights went off after its 12hr cycle.
> 
> So if pressurized CO2 can be ran 24/7, diy is a joke and will present no treat at all. I did diy co2 for a year when I first started out in 02' and it wasn't as technical as it is now. I couldn't even remotely tell you how to stop CO2 from a diy setup way back then and I wouldn't worry about trying to stop or regulate it now. If you find yourself needing to regulate the flow, this is when you jump to pressurized.


My DIY CO2 as controlled by a solenoid, often sits at around 15PSI, which is exactly what you will get after regulating the 'pressurised' CO2. I don't see how there is any difference to be honest. I have enough capacity to maintain a constant pressure and regulate via a needle valve and solenoid.


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## matt85 (Jan 9, 2015)

Hello all

I was wondering if you could sanity check my idea. All constructive criticism is welcome, as this is just an idea on paper at the moment. I am looking for a controlled way of delivering CO2 to my aquarium, to minimise the risk of over dosing CO2.

I am planning to make a DIY CO2 contraption for providing CO2 to my 75 litre. The contraption will have a reaction vessel (consisting of a 1 litre plastic pop bottle or glass wine bottle- I am yet to decide) containing 500mL of malted vinegar (5% w/v acetic acid). The reaction vessel will be linked to a second vessel and a syringe containing sodium bicarbonate solution. The second vessel will contain water and act as a gas separator and will be further linked to the aquarium water via a diffuser. I will attach valves between each of the components so each can be isolated if needs be. The plan is that the syringe can be used to supply a dose of sodium bicarbonate to the acetic acid which will react and produce CO2. The CO2 will bubble through the gas separator and then into the aquarium, with flow being controlled by the valves. As only a small amount of sodium bicarbonate will be supplied in each dose, there will be no chance of over dosing the CO2 and pressure will remain within manageable limits (and there will be no explosions!).

To further lower this risk, the concentrations and proportions of the two reactants has been calculated. The target CO2 concentration in the aquarium water is 20ppm or 20mg/L. For a 75 litre aquarium this means that 1500mg (1.5g) is required. As the molecular weight of CO2 is 44.01g/mol, 0.034moles of CO2 is required. The balanced reaction tells us that one mole of sodium bicarbonate and one mole of acetic acid produce a mole of CO2, hence the dose of sodium bicarbonate must be equal to 0.034moles (around 17ml of a 2 molar solution, produced by dissolving 168g in 1litre of water, as it's molecular weight is 84g/mol). Malted vinegar contains 5% w/v acetic acid so the 500ml in the reaction vessel contains just over 0.4 moles (5% w/v gives 25g in 500ml, whilst acetic acid has a molecular weight of 60.05g/mole). This means that there can be over ten doses of sodium bicarbonate before the acetic acid will be depleted and CO2 production will cease.

I am obviously assuming that all carbon dioxide will be diffused successfully and that each dose will last a reasonable amount of time (a few days would mean a month could be achieved before the vinegar would need replacing).

I hope that anyone with experience of using CO2 could point out any major oversights and/or changes needed before I attempt to make this.

Thanks


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## Hilde (May 19, 2008)

Jubs said:


> I have this system and have been logging progress on my club's mailing list for Gary Lange


Got a link to Gary Lange? How much of citric, soda, and water did you use?


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## jrill (Nov 20, 2013)

Hilde said:


> Got a link to Gary Lange? How much of citric, soda, and water did you use?


If this helps here is a link to my posts on citric acid.
http://www.plantedtank.net/forums/showthread.php?t=815241


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## Hilde (May 19, 2008)

maxham51 said:


> The real problem is not the price difference but that you have to readjust the needle valve with each refill. This problem can be solved by inserting a ball valve on a tee just before the needle valve.


Do you mean the ball valve goes in the line between the 2 bottles? I can't comprehend how this works for Bottle B with the needle valve and baking soda has to restarted too, does it?


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## Hilde (May 19, 2008)

EvilFish said:


> Nope. Just use half of dose (I use 25% of dose acid citric & soda). It's good for 2 weeks and pressure will never up too much.


So in Bottle A 3.5 oz of citric acid and 10oz of water and in
Bottle B 3oz of citric acid and 4oz of water


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## Hilde (May 19, 2008)

ajwan said:


> I prefer to leave it at 1.5 kg/cm2. I've had my unit going on for the last 3 days (on 12 hours, off 12 hours). Given the rate of citric acid depletion, I would estimate 1 - 2 months


Well how long did it last? What is your formula for bottle A and B?


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