auto-topoff storage problem

[NateHanson]

I know the float valve shuts off flow from the RODI, so it never overflows, but if water is constantly being drained very slowly from the bucket, so that the float valve is often just a little bit opened, doesn't the waste-water continue to flow through your RODI? Because with the valve slightly opened, there isn't sufficient backpressure to activate the ASO. That's what's happening with mine, maybe yours is different. If I'm in the basement, I can hear the RODI draining water quite often during the day, even though my basement reservoir is full, but in the sump water is just very slowly dripping out of the float valve, because that water level is just a smidge below the float valve shut-off level.

 

[nunofs]

After realizing that my tank is evaporating more than 1g/day, and faced with a 5-day vacation in the near future, I just bought a double-switch sump-mount top-off (how's that for hyphenated words?!? ) controller from autotopoff.com.

They can have it done in one of two configurations: for use with a reservoir (1st switch is master, 2nd is only backup) and for use with a RODI (1st switch turns on, 2nd switch turns off -- exactly to avoid having the RODI run every time the water level drops a little bit)... you can also get a solenoid valve from them for the RODI setup. I'll post again when I receive it and set it up.

Btw, I realize you probably can get it done for much cheaper than what they're selling it for, but at this point I don't have the time and patience to go look for all the supplies and to try and make sure that it all works together, so I went with the pre-made solution...

Nuno

 

[NateHanson]

thanks for the heads up nuno. I'll take a look at that too.

 

[JustDavidP]

Nate, When Gumhead and I set up the rig, I asked the same thing.

While the sump is calling for water constantly, the RO/DI reservior is not. Again, I do physically valve off the RO/DI unit from the barrel when it is full (unless I forget). When the valve is closed between the barrel and the unit, it creates a significant enough back pressure to shut down the RO/DI. I'm sure that if the entire system was constantly "trickling", the waste water would be rushing through my drain pipes.

 

[~Flighty~]

My rig looks something like this...

It consists of an Auto Shut Off Valve on the RO/DI, a 20 gallon brute barrel, two float switches, some bulkheads with quick connect connections, and some tubing.

Pardon my cartoon like sketch I'm a reefer..not architect.

Dave

Can I get a frag of the second coral from the left?

 

[NateHanson]

Hey guys, here's exactly what I was trying to figure out before I started this thread. A totally mechanical method to cycle the RODI less often. Much cheaper than all the switches, relays and solenoids. Very cool. Based on the idea of pulling an upside down glass with water. Imagine your float valve in that glass. It doesn't empty until the water around the glass drains to below the lip of the glass. I had it all sketched out, but I couldn't figure out how to negotiate needing a vent to fill the glass, and needing a vacuum to keep the glass full. It's all solved by a simple air check valve. (Silly Nate!)

What do you guys think?

 

[JustDavidP]

Cindy... you make me giggle... and today, that's a hard thing to do. Sick kid, my car got whacked in a parking lot.. typcal Monday. Thanks for the laugh.

 

[JWeb]

Nate, as long as the low-level and high-level switches are controlling the solenoid valve, I can't see why that wouldn't work. In fact, that setup could get you completely away from 120VAC (required to run the powerhead). I'm quite sure I saw a 12VDC-switched solenoid valve on McMaster. Of course, it would eliminate the float valve, as well - probably another plus. Good thinkin'.

IN FACT: If the solenoid was a normally-closed type, you could place ANOTHER float switch slightly above your high-level switch (except inverted) and wire them in series. In this way, if the high-level switch gets stuck, the rising water would trip the "failsafe" float switch and interupt power to the solenoid valve - thereby closing it. Good stuff.

Write-up on the control circuit is still pending...

Jeff

 

[NateHanson]

Ooop! I forgot to paste the link to the reefcentral thread that describes the "upside down glass" method.

Sorry

http://www.reefcentral.com/forums/showthread.php?s=&threadid=275455&highlight=solenoid+valve

 

[JWeb]

Nate, I'm intrigued by your purely mechanical idea, too - but I'm not quite visualizing what you are proposing (no pictures in that thread). Yet, when I consider vacuums, pressure and sealing with respect to a system in a fish tank, I worry. Do you think you can get it to be stable/reliable?

Jeff

 

[NateHanson]

I forgot the link at first, but check out the RC thread about this. Sounds very stable/reliable. And very cheap to build. The only drawback I can see so far is a gurgling noise when the system resets.

 

[JWeb]

Nate (et.al.), I just posted my write-up for the DIY ATO system if you are still interested.

I'm really curious about this mechanical solution, however. Do you plan to try it?

Jeff

 

[NateHanson]

Yeah. I have it drawn up, and I'm going to build it as soon as I get a check valve in the mail (free sample! )

Nate

 

[JWeb]

I don't see any photos in that RC thread... were the supposed to be any? I have some questions that I think would be answered by the pictures...

Also, where did you find the check valve? I've been looking for a low-cost supplier...

Jeff

 

[NateHanson]

USplastic has a few. They're a diaphram type that should work, and they're super cheap. I posted the model number in the RC thread

The photos seem to have been removed from their original source, so they're not showing up in that thread. I agree it would answer some questions I have too.

Primarily I'm wondering what he means about positioning the box so a sheet of air enters all at once.

I'm designing mine to fit under my cramped stand, so it's only going to be 11x6x6, and the float compartment will be 2" wide (just big enough for the float valve). It will probably cycle about twice per day.

If the valve I'm getting has a 2" crack pressure, do you think that means the water level in the main reservoir will be 2" higher than in the float reservoir? (so I should adjust the float valve to be at least 2" from the top?)

 

[nunofs]

I just bought a controller from autotopoff.com.
I'll post again when I receive it and set it up.

I received the controller today and have just finished setting it up... it's pretty simple... I got the model with the primary and backup switches, it's just a matter of attaching them to an acrylic piece (with zip-ties) at a height determined by the desired water level. I'm using a maxi-jet powerhead inside a plastic container and it pumps water into the sump whenever the level drops. Seems to work fine so far. Now I just need to find a narrow, tall container that fits inside or behind my stand and takes at least 7 or 8 gallons and I should be all set for vacation

Nuno