My Automatic Water Changer - Setup

[SuRje1976]

Originally Posted by steve5520

mine seems like it flows faster.

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

Originally Posted by steve5520

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.

Originally Posted by steve5520

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,

[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.

[SuRje1976]

Originally Posted by steve5520

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.

[SuRje1976]

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

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

[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.

[Betowess]

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

[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?

[Betowess]

Originally Posted by 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 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.

[Hoppy]

Originally Posted by SuRje1976

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.

[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.

[SuRje1976]

Originally Posted by Hoppy

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!

[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

[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???

[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...

[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.