# My Automatic Water Changer - Setup



## Mori

I need a few minutes to absorb this, but I like it. Are you using RO because it's convenient to plumb? Or so you don't have to use dechlor?


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## fresh_lynny

nice set up and explanation!


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## steve5520

_"This is all going to sound a bit insane, and I know I'm going to take some heat for it, because it really isn't that much effort involved in doing a weekly water change. The way I justify it is, now I have an extra hour a week to spend with my wife and daughter. I needed to prove to myself that it could work. What I realized is that there are quite a few ways to skin a cat."_

The way I looked at it, being automated, I no longer have to REMEMBER to do it. Or make sure I have the time.

My setup is nearly identical, with 2 exceptions. First, I have a $40 solenoid on the drain line. I go down to 3/8 tube for the drain, so it takes much longer to drain enough water out of my 150 gal tank. I timed filling a gallon jug and did some quick multiplication.
Second, I don't use RO, so the solenoid for that is just hooked to the water supply (just like an icemaker). That's controlled by a float valve in the tank. So I kill two birds at the same time. Autotopoff and water change. The drain solenoid is on a timer, right now I do once a week. I'm considering a little less per change, but going twice a week.

Dechlor? Don't know what to say. I've had freshwater tanks for many years and never used it. Haven't seen problems yet.
And the way mine is now, it takes about 2 hours to change 40 gallons, so the new water is going in farily slowly. I believe chlorine will disapate on it's own fairly quickly.


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## Betowess

Oh, fun to read and re-read and re-re-read and contemplate!


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## SuRje1976

Mori said:


> Are you using RO because it's convenient to plumb? Or so you don't have to use dechlor?


No, actually it would be easier for me to dose dechlor via liquidoser than to reconstitute to desired GH. The plumbing could be done identically for regular tap water as well. I'm using RO because my plants seem to like a very low KH, and the municipal water available to me has a KH of about 3-4. Check this out if you have time:

http://www.plantedtank.net/forums/g...iscussion/32365-low-no-kh-low-ph-without.html


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## SuRje1976

Brilliant said:


> so I am unplugging the solenoid after I use the water then plugging it in day later to make more


You plug your current timer into a timer that was set for 12 hours on, 12 off - that would give you every other day as long as there is not battery backup in your current timer. It would also be quite large I suppose. That said, X10 is about as flexible as it gets!


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## Betowess

Sergio, why do you need an electronic valve into the drain line, after the pump? Is it to keep any drain water from approaching the pump when the pump/output water is not being operated? Must be. This is definately going to be one of my next BIG projects! Luckily my fishroom is right next to our utility room and I think I can get by without the RO setup. 

Also, that is a fairly spendy solenoid. What is the advantage? Is it more reliable than others...why did you opt for that particular unit? 

Last query. What kind of timers are you using... Digital?
TIA and thanks for posting. Very informative.


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## SuRje1976

Betowess said:


> Sergio, why do you need an electronic valve into the drain line, after the pump....
> 
> Also, that is a fairly spendy solenoid. What is the advantage? Is it more reliable than others...why did you opt for that particular unit? TIA and thanks for posting. Very informative.


Bob,

The solenoid is there because the pump is not capable of stopping the forward flow of water to the drain line when it is off. If it wasn't there, the tank would be constantly draining because it is plumbed to the canister. I initially was going to drain directly from the tank via the pump, but then I'd have an issue with the siphon that would be started. I did come up with a solution for that, but opted to plumb to the canister so there was one less item in the tank.

I think the solenoid was overkill. My original justification was the 3/8" opening it provided. This prevents excessive back-pressure on the pump. Steve (scolley) pointed out that I could have run a few MUCH less expensive RO valves in parallel. :icon_redf Don't tell my wife!


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## scolley

Sergio - Congrats on a very nice setup! Something that can make everyone's life easier to be sure. :thumbsup: But it has certainly peaked my curiosity...

As you know, I've been working on something dramatically similar. So my apologies in advance for asking some rather direct questions. But here goes...

_How accurate have you found that sensor to be?_
While my objective in creating something similar was a bit different from yours (detecting pressure from the bottom of the tank vs. sensors hung over the side), I spent a good bit of time researching air pressure senors like yours. I even bought two different ones for testing, though not the Spectrapure, which is at the top of the price range for such items.​

_Have you found the readings to remain consistent over time? _
What's the variance day to day? How many weeks have you tested? I found the variance over time (multiple weeks) for similar air pressure sensors to be quite significant. I always suspected that's why Spectrapure sold the accompanying "safety" float valve.​

_If it works, why does Spectraput supply a safety?_
I ripped my air pressure sensors apart to get to the hardware, then grilled the manufacturers about their specs. My findings weren't good. Hopefully Spectrapure is investing in better senors than the products I looked at.​

Please let us know if this solution is accurate over time, or has to be regularly re-calibrated. Thanks.


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## steve5520

_"I could have run a few MUCH less expensive RO valves in parallel."_

I had never thought of running parallel valves. It would certainly drain faster than it is now.

On the other hand, the way mine is setup, I guess I'm really not concerned with draining rapidly. The way it is now, it drains for a bit, then the float valve kicks in and it refills. The whole time, the drain is going, the topoff (fresh water) is kicking on and off.

I have a digital timer set for just under 2 hours, once a week. It takes somewhere around 2 1/2 minutes to drain a gallon. I'm sure the amount draining will vary some depending on flow through the filter, but I'm not sure how drastic it will be.

I guess I figure too, make the error to the high side, change more than I think I should. That way it will probably be enough.


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## SuRje1976

Steve, thanks for the kind words!



scolley said:


> _How accurate have you found that sensor to be?_


Usually to within 1/4 inch of depth.



scolley said:


> _Have you found the readings to remain consistent over time? _


NO. The level varies due to a few things -ambient room temperature, and I *think* that pearling plants may throw it off too. When a bubble rises under the sensor it increases pressure on the valve and feed water stops SOONER. This translates into a lower water level in the tank.

That being said, I think I've found a way to deal with it. Once a week the tank drains for 25 minutes (as opposed to 20)(X10 timers are great). This brings the water level BELOW the sensor COMPLETELY, exposing its base (open end) to the air, re-equalizing the pressure that will be applied to the valve.



scolley said:


> What's the variance day to day?


None detectable from one day to the next really. Over a week, 1/8 to 1/4 inch.



scolley said:


> How many weeks have you tested?


Hmmm...today completes the 4th week with the sensor.



scolley said:


> I found the variance over time (multiple weeks) for similar air pressure sensors to be quite significant. I always suspected that's why Spectrapure sold the accompanying "safety" float valve.


As did I, but the once weekly longer drain (so far) has COMPLETELY addressed that issue. One thing worth noting though, is that the tank level has NEVER varied in the upward direction (yet). We'll see what happens when it gets colder, but again, I think the weekly "reset" should take care of it.

If I have ANY issues with the tank level (I really don't expect to) or the level conrtoller itself, I will report it here AS SOON AS I DRY MY FLOOR!!! I promise!


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## scolley

SuRje1976 said:


> I think I've found a way to deal with it. Once a week the tank drains for 25 minutes (as opposed to 20)(X10 timers are great). This brings the water level BELOW the sensor COMPLETELY, exposing its base (open end) to the air, re-equalizing the pressure that will be applied to the valve.
> 
> 
> None detectable from one day to the next really. Over a week, 1/8 to 1/4 inch.


Thanks for the candid replies Sergio. Your findings are completely consistent with my own. Well, not with respect to cycles, since I tested running 6-8 cycles a day. But certainly with respect to time.

I found the periodic "reset" to work just as you have. It is essential. Most of those air pressure sensors have, unbelievably, pressure sensitive membranes that are... hold on to your hat... AIR PERMEABLE. Go figure! So drift is inevitable.

But you have found the solution that makes them workable, so you should document that periodic "reset" with your solution. IMO it is an essential part of your solution.

Congratulations on finding something that works well! Please keep us posted on progress.

PS - Thanks for the careful, accurate observations. That's what we all learn from. :icon_wink


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## SuRje1976

Steve,
I was actually depending on someone (you) to ask those questions. I knew that they were issues that HAD to be addressed in order for this thread to be worthwhile, but I thought that they would be too much to present in the original post.

So thank YOU!


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## steve5520

Sergio, neat setup.

Just a question. Have you ever tried the setup without the Eheim pump between the canister and the valve? I only wonder because my drain setup is very similar to yours, but mine seems like it flows faster.

I have a Filstar XP3 (rated at 350gph, probably empty). On the return line, I have a 5/8 to 3/8 reducing tee. From there I go to a solenoid valve which is much smaller than the one you have (should be flowing less). And yet, I can drain a gallon in less than 3 minutes. That would only take 12 minutes to drain 4 gallons.
Originally, I was using 1/4 tubing as nothing more than a siphon (not connected to the canister) and that was draining a gallon in about 3 min 40 seconds. Not that awful much slower.

Just seems like you should be draining way faster (not that you need to) if the pump is effective at all. Maybe it can't pull water from the canister fast enough to help much. And if it did, would there be concern about cavitating the canister?

Just wondered. Save a little electric if you really didn't need to pump it again.


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## SuRje1976

steve5520 said:


> mine seems like it flows faster.


Steve, what length of tubing does your waste water have to pass to get to your drain? 



steve5520 said:


> Just seems like you should be draining way faster (not that you need to) if the pump is effective at all.


It is actually a bit slower without the pump. Takes about 35 minutes (still not unacceptable) to drain ~4 gallons as opposed to 20, with.



steve5520 said:


> Maybe it can't pull water from the canister fast enough to help much. And if it did, would there be concern about cavitating the canister?
> 
> Just wondered. Save a little electric if you really didn't need to pump it again.


I initially was concerned about this as well. I was expecting that if the pump could NOT pull water fast enough from the canister, it would certainly be able to REVERSE the flow of the Lily Outflow. That would be a problem because the water level drops BELOW the outflow. But it DOESN'T reverse the direction, leading me to believe that the limiting factor MUST be the back-pressure from the length of tubing in the drain line. What I have yet to determine is if the pump will be able to stand running with that back-pressure intermittently for months/years? If it burns out, I will *might* not replace it. One could certainly set this up without the pump, but then the flow rate from the canister would have to be factored into the timers somehow. Right before I clean my canister and replace the floss my flow rate is noticably less than right after it's been cleaned. 

Thanks,


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## steve5520

_"Steve, what length of tubing does your waste water have to pass to get to your drain?"_

Not very long. It runs about 4 feet then I have the solenoid valve. Another 8 inches or so and it goes into a 90 nipple right into the drain cap. I'm lucky, mine is set up in the basement, so I has close access to water pipes and drains. I would guess the 90 is adding some restriction, probably flow better if I just stuck the hose directly into the cap. I just wanted it to look nice.

I think the only reason I asked is because I know the port sizes on the solenoid valve I have must be my limiting factor. It's only one of these:

AutoTopoff.com

Instead of quick connects I put 3/8 barb fittings. But the threads in the valve are only 1/8, so how big can the ports be?

I think I don't have quite as much concern as you about the timing of the drain cycle. The topoff system you have is a bit more sophisticated than the simple float valve that I'm using. If my flow is off, I'll just be changing a little less water, depending on what day of the month it is. I figure I should go a little over anyway, since I'm adding and draining water at the same time. Not exactly in sync, the fill is faster than the drain. The fill just kicks on and off during the whole drain cycle. I drain from one end of the tank (filter input) and the topoff water is going in the other end of the tank. 

I think I am going to change my timer though, and do more like you are. Some every day. I initially had it for once a week. About a 25% change (approx 40 gal of a 150 gal tank). I considered going Mon, Wed, Fri and doing a bit more over the week. Maybe 15 gal a day would be better? I'd like to hear your thoughts on frequency.
I do have pressurised CO2 and a controller. Right now, I am manually adding excel and flourish.


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## SuRje1976

steve5520 said:


> I think I am going to change my timer though, and do more like you are. Some every day. I initially had it for once a week. About a 25% change (approx 40 gal of a 150 gal tank). I considered going Mon, Wed, Fri and doing a bit more over the week. Maybe 15 gal a day would be better? I'd like to hear your thoughts on frequency.


There is a calculus equation that can determine the amount of water you would need to change daily to approximate the 50% weekly water change many are doing. I don't remember the details of the equation, but I DO remember that it always worked out very close to 10% of the tank volume - so that's what I do.

Most of the people I spoke to researching this said that the more frequent (smaller) changes are better for the tank. I really have not been doing them at this frequency long enough to tell you exactly what I think. My Tonina look much nicer, but that may be because I've been working to reduce my KH over the past few months. I'm at a pretty steady KH now, so I will have a better idea of how the livestock responds in another month or two. One thing I CAN say for sure is that it certainly is causing NO harm.

I'll get back to you.


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## SuRje1976

*An Update, bad calculation*

Just wanted to post an update. I had miscalculated the amount of Equilibrium that I should have been adding to keep my gH at 5, where I wanted it. I decided to test today because I noticed some wrinkling on my Ammania, and a pinhole here and there on my Hygro. 

Turns out that I miscalculated the dose of Equilibrium I was supposed to be adding. My gH was at 1.5 and my K was at about 10ppm. I don't dose K2SO4 (as of yet) so I depend on the Equilibrium for some of the K.

This affects my autodosing. My Rondomatic 400's compartments are actually not big enough to hold the proper amount of Equilibrium for once daily dosing. So, I've switched to twice daily, and recalculated the doses for KNO3 and KH2PO4, as I've decided to dose them daily as well. The first dose drops right after the drain sequence, and the second right before the fill sequence.

I HAVE decided to drain at midnight, and fill at 8am. This allows for better nighttime aeration due to the lily pipe being above the water level.

I got a scale to weigh out the ferts for unnecessarily accurate dosing. Now between my electric bill being outrageous, and purchasing an extremely accurate scale, I'm a little nervous about provoking an DEA investigation:icon_roll 

I just hope that when they break down my door, I'm not actually weighing out the ferts. That would look REALLY bad.


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## Betowess

Just get a few MH lights and they'll be there in no time. And be sure to measure your K2SO4 with the blinds down so they can get a good picture too.


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## Betowess

Do you guys think this solenoid valve would work OK for drain purposes.
OMEGA-FLO® 2-Way Zero Differential Solenoid Valves


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## SuRje1976

Bob, It looks like it would work to me. You would probably want to go with the SV3503 or SV3504, for the increased Cv. You may want to call them to ensure that they can supply you with an electrical connection that is waterproof. You'll probably have to set the electric supply connections up on your own. I had to anyway - took a few phone calls, but I got it done. You are probably going to want a check-valve on the tank side of it to be safe, not sure what metals they use in the solenoid (site states only brass & SS). You have shrimp if I remember correctly no?


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## Betowess

SuRje1976 said:


> Bob, It looks like it would work to me. You would probably want to go with the SV3503 or SV3504, for the increased Cv... You are probably going to want a check-valve on the tank side of it to be safe, not sure what metals they use in the solenoid (site states only brass & SS). You have shrimp if I remember correctly no?


Thanks for your help Sergio. Yeah, I was concerned with the brass element and am going to search for something made of plastic if possible, like the one you went with. I'm also contemplating using a smaller solenoid and doing smaller changes more frequently, although T. Barr recommends larger ones. My water is pretty cold out of the well tap, so I don't want to freak the temp out too much. If I go smaller more frequent, wouldn't a smaller diameter suffice(such as 3/8 or 1/4" NPT)?

I suppose I could put an inline heater on the return to help out as well.


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## Hoppy

SuRje1976 said:


> There is a calculus equation that can determine the amount of water you would need to change daily to approximate the 50% weekly water change many are doing. I don't remember the details of the equation, but I DO remember that it always worked out very close to 10% of the tank volume - so that's what I do.


Here is a handy calculator that figures this out for you: 
Drip System Water Change Rate Calculator (W.C.S. Ltd.) . I checked its accuracy for my system, which I had to do the manual calculation for, and the calculator agrees with my calculaton.


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## SuRje1976

Bob - you could definately go with a smaller one, just depends on how fast you want the tank to drain. If you're going to use a pump to assist the drain, just make sure to get one with an output diameter similar to the smallest diameter in the drain line, whether it be the valve, or the tubing itself. As far as temp, I've had no issues. I fill directly from a R/O DI Unit, so the flow is very low. I'm doing 10% daily (refilling 4 gallons over 40 minutes), so the 2128 heater would certainly be suffucient to take care of any potential temp drop if it was to occur. You could use RO tubing for your fill line and plumb a ball valve inline to slow the feed. I do it overnight, so there is no rush. 

I just checked out the spec sheet on the valve you found, and there is copper in it. Not really sure if that will be an issue with the shrimp. I suspect not, especially with a check valve in place.


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## SuRje1976

Hoppy said:


> Here is a handy calculator that figures this out for you:
> Drip System Water Change Rate Calculator (W.C.S. Ltd.) . I checked its accuracy for my system, which I had to do the manual calculation for, and the calculator agrees with my calculaton.


Thanks for the link Hoppy!


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## Betowess

I am concerned with the speed/power of a direct return from my water line, not to mention water pressure. But then I read your suggestion of a ball valve which is what I was thinking of - to slow the flow abit. I'm curious what Steve did with his setup, since he didn't use an RO system either. Lots to contemplate (fun stuff!). I'm leaning toward plumbing with PVC most of the way to and from the tank. We have cats and dogs and hose makes me a little nervous.

Steve5520, what size and make of solenoid are you running for the return line. Can you describe the sequence. House's water line to solenoid to tank etc... Is it a separate line into the tank? Not from the canister's return? TIA


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## SuRje1976

I think the ball valve should be fine, assuming your water pressure is fairly consistent. I could have sworn I saw a non-RO flow restrictor somewhere, but I can't find it now. I spent the last half-hour looking! That would be ideal - the RO restrictors are designed to allow a specific max flow, eg. 150mL/min on a 100gpd RO unit. I'm thinking no such monster exists for tap. Anyone know of such a thing???


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## Betowess

Well, my water pressure is inconsistent. A well house sets it at (I think) ~60psi or so, but it really does vary. When the well house's pressure pump is running it totally cranks. Then it drifts to less pressure when that well pump is off. Maybe I'll have to go the RO way... But would it matter if the fill cycle is slower? I suppose not if using a float. It would just take longer, right? But I suppose that messes with timers if not using the float. I didn't want a whole bunch more stuff _in this tank_. But this is going to be a dry run (well, a wet run) for an auto fill for a future, slightly longer tank, hopefully...


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## steve5520

My water pressure is usually around 50 psi. Stays pretty constant unless there are problems with a water main.

To clarify my whole setup, the INLET side of the setup is an Autotopoff system. It's a solenoid valve, control box (relay setup) and a float switch. When the level in my tank drops around 1/8 inch, the topoff kick on. Whole thing is plumbed with 1/4 inch poly tube, just like an icemaker.

I've used these also:
Aquahub Homepage
and they are cheap and easy to build.

For the DRAIN, I have a TEE in the return on my Filstar XP3. From the TEE, I have 3/8 clear tubing going to this solenoid valve.
AutoTopoff.com
That solenoid is hooked to a TIMER. When I want to change water, the timer kicks on for a specified time period. It takes just about 4 minutes to drain ONE gallon of water. So in one hour, I drain 15 gallons from my 150 gallon tank.

As soon as the float senses the water level going down, it kicks in to start refilling the tank. The fill time is faster than the drain time. The fill kicks on and off over the water change cycle.

Right now, I do this once a day, which according to the chart posted, should be around a 50% change per week.


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## Betowess

Steve, are you doing any fail safe stuff on the top off (inlet)? Like two of the float switches like I saw on one of the websites you linked me... And you might have already told me this... Are you running the 12/16mm or ~3/8 hose or pipe on that inlet side?
Is it the same 12/16mm hose for the drain? Thanks! bob


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## Betowess

He's not running RO, just tap, I believe.


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## steve5520

"are you doing any fail safe stuff on the top off (inlet)? "

No I'm not. It's just a single float switch. Maybe one day it will bite me, but the worst that can happen is for the tank to overflow. Since it's in the basement, the mess wouldn't be too bad.  

I ran a top off on the reef setup I had for nearly 2 years, never even had to clean a float switch. I guess I'm figuring that salt and calcium would cause problems faster than freshwater, so I'm okay with a single float. If it were in my living room it might be a different story.

Try to make this concise:
Inlet side:
Float switch controls the level in the tank. Solenoid is hooked to cold tap water with 1/4 poly tube, same as an icemaker setup. My water pressure floats right around 50 psi and I estimate that the Clippard valve I'm using
http://www.clippard.com/store/display_details.asp?sku=MME-2QDS-W110
will pass around 50 - 60 gallons per hour. It only cycles on and off during the drain cycle.

Drain side:
Tee is in the return on my Filstar XP3.
Black Lightweight High-Density Polyethylene Tubing And Hose Tee Barb Fittings - US Plastic Corporation
Tee is 5/8 x 5/8 x 3/8
3/8 clear tubing runs to a solenoid valve.
AutoTopoff.com
Solenoid is controlled with a digital timer. 

Volume of drain was obtain by timing how long to drain one gallon. After that, it was easy to figure how long I needed to leave the solenoid open.

RO water would not be as easy because of how slow it is produced. When I had the reef, I had a 100gpd ro/di. What most people forget is the 100gpd rating is at test pressure and temp, which I believe is 50 or 60 psi depending on who's membrane it is and 77 degrees. Lower pressure and temp will reduce ro production a LOT. With my 100gpd unit during winter months, I'd guess I was getting maybe 50-60 gpd. That's only 2.5 gal /hr


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## Betowess

Steve. I just printed out your PM and you had already covered almost all this- my bad - but at least its here for everyone. I might end up with Sergio's pressure water sensor, but I'm going to start with the auto top off to keep the cost down. This is quite doable and I am really happy about it. Thanks for sharing!!


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## SuRje1976

steve5520 said:


> With my 100gpd unit during winter months, I'd guess I was getting maybe 50-60 gpd.


Steve - thanks for sharing! I just got my RO/DI unit in June, and I didn't even take this into consideration. I may need to adjust my timers to make sure the tank refills completely.


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## steve5520

Here's a link to a chart that you may find useful.

Calculating Expected GPD-LPD from the Reverse Osmosis RO Membrane by SpectraPure Water Purification Systems

As pressure drops, output drops. As temp drops, output drops. As far as I know, you cannot compensate for low temp by raising pressure.

One trick (cheap) that some reef guys do is to buy a coil of 1/4 poly tube, maybe 50 to 100 feet. Coil it up and put it in a bucket. Fill the bucket with water and stick and old heater in there set at around 78 degrees. It will warm the input water up and help maintain a little better output.
You can also find "mixers" to mix cold and hot water before entering the ro unit. From what I read, they aren't all that good. You need to be cautious too, water too hot will ruin the membrane.


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## SuRje1976

steve5520 said:


> Here's a link to a chart that you may find useful.
> You can also find "mixers" to mix cold and hot water before entering the ro unit. From what I read, they aren't all that good. You need to be cautious too, water too hot will ruin the membrane.


You know, the thought crossed my mind to tinker with ball valves set at specific levels of "open-ness" on the hot and cold line to achieve a specific temp to the RO/DI, but as my water chenges are done overnight, I don't think I'm going to run the risk of ruining a membrane. I'll just start the fill sequence at 6am, instead of 7am. Thanks again Steve for the info!


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## Betowess

Any thoughts on running 3/8 clear hose or is 3/8 RO hose similar for the drain. I don't want to chance a bend in the hose restricting flow. Which would be better, or does it even matter. I am leaning toward getting a Hobby pump like you have Sergio, since my distance will be around 22 feet give or take a few feet. Thanks for all the help Sergio! I'm about to start ordering components!!


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## SuRje1976

Betowess said:


> Any thoughts on running 3/8 clear hose or is 3/8 RO hose similar for the drain. I don't want to chance a bend in the hose restricting flow. Which would be better, or does it even matter. I am leaning toward getting a Hobby pump like you have Sergio, since my distance will be around 22 feet give or take a few feet. Thanks for all the help Sergio! I'm about to start ordering components!!


Bob - I don't think that it will make a difference except that you may have an easier time making your connections if you go with RO tubing. The John Guest line of adapters make plumbing the system pretty easy, and very leak resistant. PLUS, if you need to make a bend, you can buy things like this or this to prevent kinking. Obviously, if you have the room to make the larger diameter bend, go with that - it will have less effect on your flow rate.

One thing to keep in mind though is when you buy aquarium tubing/clear tubing, the size listed normally describes the INSIDE diameter of the tube (ID). When you are looking at RO, the measurments refer to the OUTSIDE diameter of the tubing (OD). So in that sense, they are NOT equivalent. If you wanted 3/8" ID, you would want to run with 1/2" RO tubing. That being said, I think 3/8" RO would be plenty, plus there is a wider range of fittings and adapters available than for the 1/2" RO.

I find that the drag created by the length of tubing I'm running (similar to what you'd run) to be very substantial. I really would recommend going with the pump. Just as a test, try blowing through a short length of tubing, say a foot, then try blowing through the length that you're going to run. The difference will be impressive.

Steve - thanks again for your input on the topic. It is helpful to everyone following the thread, myself included!


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## Betowess

Thanks Sergio. This is very helpful information. :thumbsup:


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## Betowess

*Drain/fill line check valve questions*

Now that the main components are ordered, I'm just now thinking about check valves...

OK, maybe one check valve per drain line before the drain saddles to keep any other drain water from the sink from contaminating the tank's drain line...

Also, one doesn't need one after the cannister's outflow T before the Hobby pump, right? My sequence is like yours, Filter/Hobby pump/solenoid ROline out for the drain. 

But where else? Do I need one at the end of the fill line going back into the tank? Won't the solenoid stop any reverse siphon. 

The fill sequence is: Tap - solenoid - into tank with water pressure making the push. Thanks, bob


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## SuRje1976

Betowess said:


> OK, maybe one check valve per drain line before the drain saddles to keep any other drain water from the sink from contaminating the tank's drain line...


Bob, this is what I have. Very close to the drain saddle.



Betowess said:


> Also, one doesn't need one after the cannister's outflow T before the Hobby pump, right? My sequence is like yours, Filter/Hobby pump/solenoid ROline out for the drain.


I don't have one here. Don't think it's necessary. 



Betowess said:


> Do I need one at the end of the fill line going back into the tank? Won't the solenoid stop any reverse siphon.


The solenoid will definately stop reverse siphon, BUT I have one here anyway. Now I'm not a microbiologist, so I'm not sure if this is something I need to be concerned about, but the tip of the fill line is invariably going to come in contact with tank water at some point. I don't know how mobile any of the microorganisms in my tank are, but I don't want to run the risk of them "swimming" up the RO tubing to my RO/DI filter (which I also use for drinking water). :icon_eek: I HATE vomiting.


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## Betowess

I copied this from another thread for those who are following it here...

I have jumped on the auto water change bandwagon. Total Cost shipped so far: for two 3/8" Asco Red Hat solenoids, two 1250 Hobby pumps, Ro line and drain/tap connections, inlet connections etc., float switches with relays and two more 1/4" RO solenoids from Autotopoff, four John Guest 3/8" RO line check valves, two 3/8" shutoff valves, etc is about $262.00 per tank...and counting. 

I haven't added in the digital timers to the cost yet, and no doubt some other incidentals, like elec. cords and connections for the Asco solenoids for the drain cycle. This is going to be for a 90 gallon and a 65 gallon tank running around 22 feet of RO lines. Each system is independent. A little spendy, but I can't wait to see it in operation. I plan to do about 10% per day 5X a week. Then it will be just some fert dosing and trimming everyonce in a while, hopefully! Thanks for all your great help Sergio!! and Steve too!


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## Brilliant

SuRje1976 said:


> You know, the thought crossed my mind to tinker with ball valves set at specific levels of "open-ness" on the hot and cold line to achieve a specific temp to the RO/DI, but as my water chenges are done overnight, I don't think I'm going to run the risk of ruining a membrane. I'll just start the fill sequence at 6am, instead of 7am. Thanks again Steve for the info!


Use a 3 way mixing valve

I thought this was up and runnig for a while. Are you using RO/DI water directly into the tank?


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## SuRje1976

Brilliant said:


> Are you using RO/DI water directly into the tank?


Yep...been running for a little over 2 months now I guess. RO directly into tank, with Equilibrium being dosed directly via autofeeder. I'm going to need to prepare for how the colder winter water is going to affect the time the tank will take to refill.


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## Betowess

Sergio, I'm curious how you plumbed the fill line into the tank. Did you fashion some little PVC "U" or "L" shaped deal to hang over the edge? Thanks, bob


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## SuRje1976

Bob, I didn't go fancy here. Turns out the RO fill tubing fits nicely through my Coralife CF mounts. I secured it with a zip tie. All of it is under a canopy, so none of it is visible. If you're going to go the float valve route, you will NEED to secure it very solidly. It cannot move or you may get wet! The fill line will terminate at the float switch. Are you still going to go this way?


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## Betowess

SuRje1976 said:


> Bob, I didn't go fancy here. Turns out the RO fill tubing fits nicely through my Coralife CF mounts. I secured it with a zip tie. All of it is under a canopy, so none of it is visible. If you're going to go the float valve route, you will NEED to secure it very solidly. It cannot move or you may get wet! The fill line will terminate at the float switch. Are you still going to go this way?


Yeah, just yesterday I decided to try the Spectrapure "Power Liquid Level Controller" on the 90G and use the autotopoff "float switch" on the 65G. The cost is only about $15 more since I don't need Spectrapure's RO/solenoid setup. I have a spare 12/16mm Eheim OEM green round tube I could maybe use on the 65G. I'll be sure to put the fill line on the other end of the tank or pointing way away from the float... Good to know that. But the auto topoff float rig has a secure holder. Its bulky, and that's why I'm using it on my 65G where I don't care as much. The auto topoff stuff arrived today and the Asco solenoids yesterday. I just need the Hobby pumps and T and John Guest etc. The Bigal wait is on.

I'm still kicking around Steve's method of drilling a crease in the plastic lip to wedge in the RO fill line... But that idea makes me NERVOUS. Also, I'm going to pull a Sergio failsafe timer to kill power to the solenoid. Worth the extra dough, for sure.


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## SuRje1976

Betowess said:


> I decided to try the Spectrapure "Power Liquid Level Controller"


Cool! I think you'll be happy with it. The mechanics of the sensor are the same as mine, yours controls a power supply, mine controls a solenoid. PLEASE refer to post 13 for information regarding a NECESSARY periodic "re-calibration" of the sensor. You will get too much variation in the tank level if you don't do something to recalibrate every so often. The shorter the length of sensor tubing you use, the less variation you'll get. You can determine how frequently you'll need it. Best luck and keep us posted!


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## Betowess

Thanks Sergio. I routed out a threshold today to make a runway past a doorway for four 3/8 RO drain & fill lines. 

Curious, did you go Digital intermatic or X10 on your timers? I'm leaning toward X10s as its not much more money, at this point.


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## Brilliant

If I had only an hour to drain and fill my tanks using 1/4 tube and RO water from the filter I would be able to change like 2 gallons(max) of water using my 100GPD unit....and its not even cold out yet. I am waiting to see what the output is like once it gets cold.

This RO line seems ideal for auto topoff. I need BIG water changes...UNGA UNGA! Err not so big but at least 30% in a 65g or 90g. Sometimes I feel my 1/2 inch tubing isnt enough!

I am interested to see how much water your really changing in 1 hour or if in fact this process takes longer.


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## Betowess

Steve Colley cautioned me on the need to disable the "local control" feature on X10 plug and play modules. Apparently there is an easy way to scatch out a lead with a knife on the (edit) modules to disable this feature. Otherwise a power surge or whatnot might cause the units to turn on themselves. Maybe I'll go Intermatic timer after all. 
There use to be X10 modules which had the ability to by-pass this feature, but they are discontinued and I can't find any. I sure don't want any wet floors!!


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## SuRje1976

Betowess said:


> Curious, did you go Digital intermatic or X10 on your timers? I'm leaning toward X10s as its not much more money, at this point.


Sorry for the delay Bob, I've been out of town this past week. I'm using X10 timers. Haven't had any issues YET. I sure hope I don't. This is the first I'm hearing of this "defect" in the module design. I'm DEFINITELY going to look into it!!!


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## Betowess

SuRje1976 said:


> Sorry for the delay Bob, I've been out of town this past week. I'm using X10 timers. Haven't had any issues YET. I sure hope I don't. This is the first I'm hearing of this "defect" in the module design. I'm DEFINITELY going to look into it!!!



Yeah, Steve gave me some the info on this. You can do a search on disabling local control by cutting a tiny lead with a knife, apparently. But since I have 3 separate circuits in my guest room/fish room "ex garage", and X10s do best on the same circuit, I'm probably going to use some Intermatic digitals, for now. I ordered the 10X and Active Home pro, but being busy at work, I'm going to KIS and prolly return it with the 30 day grace. 

Steve also mentioned its smart to have a dark or black poly so no algae grows in the tubing, if its near any light. So I ordered some black. Puts me off $20 and another week or so, but oh well. Learning curves...


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## SuRje1976

*Rondomatic causing problems!*

I'm having a bit of trouble with the Rondomatic for dosing dry ferts. The Equilibrium is caking up in the compartments and the contents are not dropping reliably. I'm working on a system for dosing liquid ferts (GW ferts & Equilibrium dissolved) to replace it. I should have it up and running in a month. I'm going to post it when completed as it's own thread in hopes that someone will come up with a better or less expensive way to do it. Putting it together has consumed quite a bit of my free time, but it's going to _look_ very cool. 

I hope no one has purchased the Rondomatic for the purpose of dosing ferts. It makes a great feeder, but not the best choice for dosing ferts in the long-run.


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## Brilliant

Perhaps you can use a more reliable method using a liquid mix and pumps.

I was thinking about using my Reefdoser2 to supply my source water with calcium and magnesium.


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## SuRje1976

I did look at the Reefdoser. It looks like a great product! I opted for a few individual variable flow peristaltic pumps made by APT. I've got a few kinks to work out with it, but will keep you posted. I intend to put together a thread like this one devoted entirely to it. Maybe 2 or 3 weeks?


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## jmhart

Sergio,

2 years later, any major modifications to this system? Any reliability issues?


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## SuRje1976

*Jeffrey* - All is still well, all running with the original configuration! Well, not exactly. I change about 9 gallons of water (15% - the system is running on my 120P now, the 45G that it was originally installed on was torn down). The feed water comes in through a manifold I put together so that I don't have lines running over the rim of the tank. 

The water drops below the pressure sensor every night, and I do still think that's important. No, It's necessary. It "resets" the pressure sensor, assuring the desired water level upon refilling (see posts 1 and 13 of this thread).

I did have one issue that had _nothing to do with the system itself_, and everything to do with my own carelessness. I have the RO/DI unit under my kitchen sink. I installed a bypass valve around the pressure sensor valve and "T"d the output, so I could have access to RO water when the system wasn't running. I used it one day, and did remember to shut the the bypass valve BUT I forgot to close the valve on the T. When the system ran that night and the pressure sensing valve opened, instead of the feed water going to the tank, it took the path of least resistance - out the shorter T'd path and right into the cabinet under the kitchen sink! When I woke up in the morning and noticed the tank had not been refilled it didn't hit me initially. I thought "hmm...that's odd. The "on" signal must not have made it to the fill sensor." So I turned it on manually by the X10 control and laid back down. After a few minutes it hit me! OH NO! I DIDN'T CLOSE THE T VALVE! So I shot out of bed, and opened up the cabinet under the sink and realized that I was correct! 9 to 10 gallons of water in, under, behind and along the sides and back wall of the cabinet. What a pain. 

_Not an issue with the system itself_, but a mistake due to my own carelessness that I will NEVER make again. Live and learn I guess! :redface:

But all is well - thanks for asking!


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## jmhart

Thanks for the reply. I've been researching automatic water change systems where a sump has not been used, and I was glad to come across your thread, particularly regarding the Spectra-Pure LLC...what a nice device. Pretty much the answer I had been looking for... a very nice alternative to a bulky float valve.

Thanks again for the reply.


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## John_Auberry

I had mine set up so that a timer would cut on a pump for 30 seconds that fed a tube that ran into a drain. Then after the pump shut off it would still siphon until the water line dropped down to a hole drilled into the hose. Then the hole would break the siphon. Then my auto top off float valve filled the tank up. I got new hard wood floor out off the auto water change set up because of a bad bulk head. Good luck though!


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## fish geek

Ever wonder why there are no easy to install kits on the market? Seriously. I'd think one of the big companies would be all over this. 

I just built one using the instructions in the first post. Glad I found it. This thread is awesome.

For level control I used this top-off kit (on a separate timer as a safety). I bought a 2nd solenoid from them for draining.

http://fishbowl-innovations.com/product/levelController

These particular solenoids have resistance so you do need a mag-drive pump if you use them. But, they're super easy to connect. They lose points for not having a way to mount them - they sort of depend on rigid tubing to keep them stationary. I don't like that, but for $30 what do I expect, I guess. If there are better *110V* solenoids for <$30 please someone post a link.

Here are some cheap adapters for connecting the 1/4" tubing to the drain and feed lines. More handy than anything I could find at Lowes.

http://filterdirect.com/product_info.php?cPath=29&products_id=110
http://filterdirect.com/product_info.php?cPath=29&products_id=107

Hope the links help someone.

Seriously, why has nobody productized a complete kit to accomplish this? I'd think Eheim would be all over this.


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## SuRje1976

*fish geek* - Welcome to TPT! Thanks for the links. The level controller looks very interesting and is something I haven't seen before. 

That brings up a potential reponse to your initial question. I personally think it might be a good thing that there is no pre-packaged water-change system, because if we had one, there would be much less chance for innovation. More of us might just buy it, rather than trying to improve on someone else's system!


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## fish geek

SuRje1976 said:


> That brings up a potential reponse to your initial question. I personally think it might be a good thing that there is no pre-packaged water-change system, because if we had one, there would be much less chance for innovation. More of us might just buy it, rather than trying to improve on someone else's system!


Agreed. Still, plumbing is not my specialty and it's been a bit of a pain chasing down the slow leaks. Even with washers, cable clamps and thread tape...sigh. On the plus side, algae growth is down and the discus seem very happy with the daily 10% changes so it does have it's rewards.

Thanks for the welcome - I'm forever in your debt for the initial post. Never would have thought to hook it up that way. 

Still, you'd think that a profit motive would be driving innovation too. I mean if two or more big companies were fighting for market share with this kind of thing we'd see innovation on a large scale. In theory anyway.

I guess the big buys feel this is too much of a niche product.


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## Gatekeeper

fish geek.

Have you seen this site? http://www.autotopoff.com/products.html

For solenoids, i used Asco valves. You can find them all over, but if you watch on ebay, you can find them dirt cheap. I think I got my first one shipped for less thn 15 bucks (1/2"!!)

You just have to make sure that you read the fine print and buy normally closed.


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## fish geek

The more I think about it, instead of using small solenoids, I think I'm going to re-configure my set-up to use 1" irrigation solenoids. Those have threaded connectors which eliminate the problems with the ones designed for RO systems. Much less water resistance at the solenoid, and you can then build a rigid piping system that you can easily mount under the aquarium stand. This flexible tubing stuff drives me nuts. The quick connects seem to leak if you look at them the wrong way. I'm thinking that with a firmly mounted piping adapter then it'll be a lot easier to route the 1/4" stuff and not constantly worry about leaks from those Guest connectors.

http://www.sprinklersupplies4less.c...ofile=productsservices&uid=10060&catuid=10008

And at the corner Lowes

http://www.lowes.com/lowes/lkn?action=productDetail&productId=23026-147-CP-100&lpage=none

I may be selling my 1/4" solenoids pretty soon...


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## SuRje1976

Just realized that almost all of the links in Post#1 were broken. Took a few minutes to update them!


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## fish geek

I just reconfigured my changer around the 3/4" sprinkler valves. Lowes has them for about $15. They're 24V but Lowes also sells a "wall-wart" transformer for around $15 and just plug the transformers into the solenoid controller for the top-off kit, and into the drain timer. So there's no money savings on the solenoids.

But, the larger solenoid should give a lot less flow-resistance so the magdrive pump should no longer be needed. 

Here's a photo of the plumbing. The other advantage, for me, is that the PVC gives me a rigid "module" to mount under the stand, making maintenance a lot easier than untangling a spaghetti nest of Eheim tubing and funky adapters everywhere. This cost about $110 to put together including the transformers. 

Hopefully a picture is worth a thousand words.










After the glue dried I realized it would have been better to mount the ball valves 180 opposite of the way they are because then I could have mounted this right to the underside of the stand. Oh well.


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## fish geek

Here's 3 more pictures to help someone new to the idea visualize a complete installation.










This one shows the attachment to the drain and feed pipes. The adapters are from the links above (post#62). I had to drill a 3/8 hole in the drain pipe to feed the tubing through.










This shows the top-off sensor installed. It's invisible when the doors on the tanks hood are closed unless you know to look for it. Wish I could hide my CO2 reactor so easily.











I don't know if it shows in the pictures very well but since it's all inline from the Eheim filter, there's no extra pies getting water into the tank, incoming water goes through the existing Eheim tubing.

One last thing - I'm using a relatively new heater design. A Hydor Eth. They're sort of the ultimate stealth heater because they're designed to be used outside the tank. It hooks to the lines from any canister filter. I have it hooked up just after the water changer. This way the incoming cold water from the house plumbing can be heated somewhat before entering the tank.


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## fish geek

If anyone is still interested in this thread I managed to cut the draining time roughly in half.

Add a third solenoid. This one should be normally open.

Connect it in series with the output of the water changer and connect the electrical leads to the same power source that drives the pump and drain solenoid.

That way when your drain timer is activated, all the output from your canister filter is forced out the drain path, increasing the flow. When not draining, the de-energized solenoid allows the canister output to flow into the tank.

This cut my draining time from about half an hour to around 17 minutes. Not a big deal on a 55 gallon but on a larger tank I can see it making a huge difference.

The lowest price I found for the normally open solenoid was ebay (email this seller and he will have more selection than what's shown on his ebay listings). Otherwise "Freshwater Systems seems to have the best selection for normally-open solenoids.

http://shop.ebay.com/merchant/valves4projects ($49)

https://www.freshwatersystems.com/p...ormally-open-no-flow-control-stem-120vac.aspx ($70)

Of course if you use the Hydor in-line heater then that makes it more complicated...


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## SuRje1976

Brilliant, fish geek! Never even thought of doing something like that! Out of curiosity, how much water are you changing in that 17 minutes?


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## fish geek

It came about because I got frustrated at it taking so long to drain vs the short time to re-fill so I started experimenting. Figured if I _forced_ the water to all go out the drain, it couldn't hurt. Sure, it's on a timer and runs at night, but still, the engineering side of me wanted better efficiency anyway.

It's roughly 10% of my 55 gallon tank. I haven't measured the exact amount, I'm sort of eyeballing it. A 125 gallon tank would still be less than 40 minutes this way. I think above 125 gallons you'd have predrilled bulkheads so you wouldn't need a 3rd solenoid in that case since you'd already have more flow & pressure, but with the little Eheim canisters driving the flow (mine is an Ecco 2236), it makes a huge difference.


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## tazcrash69

I like the addition of the always open. That is a great idea. 
@ fish_geek: Sorry If I missed it, but what size are those hoses fro the drain? 

Not sure if it would work in all cases though
On my drain side I have a redhat that lets me use 5/8th hose, and would swear that there is a siphon from my low-set spray bar that helps me drain my 125 pretty quickly. Right now I'm only turning it on for 5 minutes, and draining about 2.5" total. 

But then again, I paid more for my solenoid than you did.


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## fish geek

Wow, that's pretty amazing. 

Yeah, these sprinkler solenoids have more resistance than I like. No doubt if I'd bought a two-way non-diaphragm instead of this sprinkler valve I'd have a faster time of it. I tried putting the mag drive pump in front of the solenoid hoping to force water through faster and that helped some but not much.

The line going to the drain is standard 1/4" tubing like you'd use for R/O. I used that because it's easier to hook up to the drain than anything larger would have been. I also use 1/4" tubing from the house cold water plumbing via an adapter behind a sink.

How much did you pay for your solenoids and do you have a link for where to get them?


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## tazcrash69

The fill one I got from AutoTopOff.com with the 3/8th fitting (since that is what my undersink carbon filter uses), and I tee'd into. 

The drain was a one time thing I found on e-bay are lurking for a long time.


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## Gatekeeper

Why did it take a half hour to drain 5.5 gallons in the first place??

I have the drain hooked up to my canister outflow line. Once the normally closed valve opens, my canister forces the water down the drain line (I get a small trickle still in the tank, but gravity does its job and forces most of the flow down).

I drain about 10 gallons in 5 minutes. 1/2" solenoid.

Just wondering why your drain is so slow...


I like your idea except for one problem, the "normally open" solenoid will gum up with stuff from the filter eventually. This could effect the orifice of the solenoid drastically. maintenance would be required periodically to keep this from happening.


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## plantbrain

gmccreedy said:


> fish geek.
> 
> Have you seen this site? http://www.autotopoff.com/products.html
> 
> For solenoids, i used Asco valves. You can find them all over, but if you watch on ebay, you can find them dirt cheap. I think I got my first one shipped for less thn 15 bucks (1/2"!!)
> 
> You just have to make sure that you read the fine print and buy normally closed.


These are good, also, the snail guard and the dual float switch is wise, alway have a back up system with something like this or go semi automated where you switch things on/off when you are there to catch things.

It takes effort and thinking to do this and plumb things, however, look at the labor you save in the process and the total lack of motivation we often have that this saves you from?
:redface:

I'd say it saves no less than 30-40 hours of labor per tank per year.
I have 5 tanks..........so that's 200 hours.
So if I paid myself 7 $ an hour, I'd save 1400$ per year. It might take me a few hours/weeks to set it up, but once done, not too bad from there on.
I'd still spend about 100$ per tank in material cost, but I'm still way ahead $ wise if labor is considered.

You can also set the system to do daily water changes, or 2x a week etc. So you can dose as much as you want.

Placing the drain and refill far apart also helps a lot to prevent in tank mixing.
There are dual set up where you can drain more %, but in general, draining a little slow(with more frequency) vs a lot fast(with less frequency) is better since it is no longer a labor issue.

But I do like to cean my tank with 50% of the water gone.

But that's gardening and I simply stop the refill part until I'm done.

The smaller % daily water changes also can avoid using dechlorinator or if paranoid, add a carbon prefilter to the refill line from the tap or use RO etc.

You can also hire a plumber to do this if you do not feel compent or hire a local friend to help that knows more about it(but don't plan on suing them if you flood your place

Regards, 
Tom Barr

Regards, 
Tom Barr


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## plantbrain

Sort of going along the lines of what Fish Geek was saying, you can oversize the drain for the solenoid, say 3/4", drain the tank in a few minutes, then have smaller inlet line to refill(say 1/4").

This will accommodate the larger % water changes without having a ot of flow coming back into the tank. Since the drain is much faster than the refill rate, you can time and set the drain to whatever desired level, say 50%. The refill tries to play catch up but cannot due to the oversized drain, but once it closes, the refill slowly fills the tank back up until the float shuts it off.

While 2 solenoids has options like this, you can do this with one solenoid, gravity and the pressure from the in line return can drain water as needed.
Same deal here, the return line that the float switch is attached to is small, say 1/4" and the drain is larger. 

All you need to have is a float switch(refill) and a single solenoid for draining.
This can be done for about 50$ or less. Mechanical float switches work, but you can pay more and get these in the links above or a spectrapure electronic etc.

Such systems really work on central filtration set ups.
But then they typically have the filter near a drain and refill and have it hard plumbed anyway. So turning a few valves is all that's needed.

Regards, 
Tom Barr


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## fish geek

gmccreedy said:


> Why did it take a half hour to drain 5.5 gallons in the first place??
> 
> I have the drain hooked up to my canister outflow line. Once the normally closed valve opens, my canister forces the water down the drain line (I get a small trickle still in the tank, but gravity does its job and forces most of the flow down).
> 
> I drain about 10 gallons in 5 minutes. 1/2" solenoid.
> 
> Just wondering why your drain is so slow...
> 
> 
> I like your idea except for one problem, the "normally open" solenoid will gum up with stuff from the filter eventually. This could effect the orifice of the solenoid drastically. maintenance would be required periodically to keep this from happening.



Good points. 

I wish I knew why the drain is so slow. The magdrive pump is rated at 250GPH. The Rainbird solenoid has barely allowed a trickle through when open though. 

I had replaced the Rainbird with a Lawn Genie valve with lower flow rate requirement and placed the pump in front of the solenoid hoping for better flow that way.

No doubt using a diaphragm based valve is the problem. 

I've seen true two way solenoid valves but none I can afford.

I replaced the white pad in the filter and will see if that makes a difference tomorrow.


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## fish geek

gmccreedy said:


> Why did it take a half hour to drain 5.5 gallons in the first place??
> 
> I have the drain hooked up to my canister outflow line. Once the normally closed valve opens, my canister forces the water down the drain line (I get a small trickle still in the tank, but gravity does its job and forces most of the flow down).
> 
> I drain about 10 gallons in 5 minutes. 1/2" solenoid.
> 
> Just wondering why your drain is so slow...
> 
> 
> I like your idea except for one problem, the "normally open" solenoid will gum up with stuff from the filter eventually. This could effect the orifice of the solenoid drastically. maintenance would be required periodically to keep this from happening.



gmccreedy -

Well, I got it draining much faster with only two solenoids. It's closer to 5 minutes now.

The whole key is that the drain solenoid should be one designed for "gravity feed" applications. Solenoids designed for auto-topoff and sprinkler applications won't work for draining because they require high pressure to operate the diaphragm. 

This ebay seller carries lots of different configurations. If you don't see what you want in his auctions, email him direct and chances are he has something that's not listed. The one I bought was $45. 

http://stores.ebay.com/valves4projects

By the way, gmccreedy, could you please post a picture of your setup? Actually, I wish everybody would post pictures, it would help newbies like me to see all the different configurations...


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## Gatekeeper

My Water Changer

The equipment setup is a bit different now, but the same stuff is used. I have the solenoids now mounted on the basement ceiling below the stand, and all tubing runs up through the walls into the stand. But it is still the same principle.


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## jmhart

For those of you refilling from an RO/DI and using an auto water change, how do you reconstitute your RO/DI? I'm guess you simply mix it in with your macro fertilizers and dose daily.

For anyone that does not use an RO/DI, but does use a auto WC, how do treat the water? Do you just dose prime via peristaltic pump?


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## Wasserpest

Peristaltic pump would be a good option.

I simply don't treat the tap water. In my case, there isn't that much Chlorine added, no Chloramine, and daily small water changes are not going to raise the Chlorine level as a 50% WC would.

Of course, everyone's situation is different.


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## jmhart

Yeah, I'm living in Atlanta where the water might as well come straight out of the backyard pool.


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## jmhart

fish geek said:


> Good points.
> 
> I wish I knew why the drain is so slow. The magdrive pump is rated at 250GPH. The Rainbird solenoid has barely allowed a trickle through when open though.
> 
> I had replaced the Rainbird with a Lawn Genie valve with lower flow rate requirement and placed the pump in front of the solenoid hoping for better flow that way.
> 
> No doubt using a diaphragm based valve is the problem.
> 
> I've seen true two way solenoid valves but none I can afford.



It's the irrigation solenoids. Those require a minimum differential pressure across the valve to open correctly. Usually it's a minimum of a 15 psig across the valve, which we just aren't going to get in, essentially, an open system(where the top of the tank is your relief to atmosphere).

I just piped in my system using irrigation solenoids for the drain, and they just can't open.


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## PDX-PLT

jmhart said:


> i just piped in my system using irrigation solenoids for the drain, and they just can't open.


_no ebay links please_

Oops, apparently forum rules prohibit posting information for the source of valves that avoid this problem. PM me if you want to know (hopefully this is permitted).


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