RO/DI Storage how to fill only when its low?

[vair]

I have 100 gallon RO/DI storage and 50 gallon mixing container. I've always just used a simple float valve to top off RO/DI storage, ATO would draw from that so it would turn on when ever needed, multiple short times all the time.

How can I let it drain say 50%+- from a water change or ATO then fill 50G then shut of again once full.

Any 'easy' ideas on this to maximize RO/DI filter efficiency. I assume solenoids which I have zero experience using? I do have a Apex controller that may aid in making it functional?

 

[dave.m]

Solenoids are simply on/off switches. They would only help if you knew exactly how long it takes to re-fill your 50 gal mixing container from the RO/DI container. Then you could use the Apex to turn the solenoid on/off to do the re-fill. You could put a second float valve in the re-fill container to shut off the re-fill operation when it reaches the top.

Personally, I am a bit leery of any automated water movement of more than 10 gallons at a time, as float switches tend to fail when no-one is watching them, especially if they become encrusted with salt, i.e. in the mixing container. I have personal experience of this.

Dave.M

 

[worm5406]

A float in the RO/DI would most likely be the best.

Set it up as a HIGH sensor and as a LOW sensor.

When the HIGH is met shut off.
When the Low is met turn on.

as in:

If outlet ROLow = ON then ON
If outlet ROHigh = ON then OFF

In that order when it gets low, to trip the low sensor, it will turn on. With there not being a fallback/set statement then it will wait to change the state until it gets to the high sensor.

You should still do the manual move to the SW mixing on your own. That way you know the amount to add instead of testing it all the time.

 

[vair]

Thanks for the feedback dave.m.

Worm that's a super simple solution, exactly what I was looking for. I have never used my older neptune for it before the Apex. Thanks

 

[vair]

Worm or others suggestion to control the drip from the filter, as no pump involved? What do i turn off and on? Never used a electronically controlled valve and that sounds like a nice failure point and over kill on a ro/di filter drip?

 

[tgunn]

I'm an doing something similar for an auto refill of my top off water. My plan is:
Float switch at high water level (ie stop filling point) and low water level (ie start filling point). Use a latching relay to activate a solenoid to fill when we hit the low level and stop at the high level ( ie see http://www.reefcentral.com/forums/showthread.php?t=1544039). For redundancy I will use a standard plastic float valve to deliver water to the tank. This way if the latching circuit fails the float valve will stop the fill. Finally I'll install a bulkhead at the absolute high point in the tank so that if both the latching circuit and the float valve fail any extra water harmlessly overflows into the drain.

I work developing a medical device for a living so I'm used to thinking in terms of FMEA analysis and risk mitigations. I think this setup should provide a high degree of reliability.

 

[worm5406]

Yes agree... The solenoid plugs into a 120v outlet (apex) so when you power it on it will open the valve and when it is powered off, it will close.


(ALSO power failure safe this way)

 

[dahenley]

if you read this thread. it shows how a person did it with his ATO containers.

http://www.reefcentral.com/forums/showthread.php?t=1482007

 

[vair]

Thanks! Slick set up.

 

[slief]

I have a 100 gallon RODI tank and a 100 gallon salt holding/mixing tank.
My RODI automatically fills up after 35-40 gallons or so is used based on where I set my float switches. The Spectrapure UHE100 RODI that I purchased included everything needed to automate that process My salt water holding tank is filled manually. MY ATO draws directly from my RODI holding tank and uses upwards of 4 gallons a day.

Typically, I will transfer water from my RODI tank to my saltwater holding tank when my RODI is about 5 gallons shy of filling itself which typically equates to my salt water holding tank being down about 25 to 30 gallons depending on my schedule and whether I am at home or travelling. RODI filters tend to last longer if they run less frequently for longer intervals that more frequently for shorter intervals. As such, I try to time my salt water mixing so that I make 60 or 70 gallons of RODI at a time as opposed to 40. Of course it doesn't always work out that way as there are times when my RODI fills itself before I make salt water but I typically mix a batch of salt water every week to 10 days and try to time it as close as possible to when the RODI is about to fill itself.

 

[vair]

Good plan slief, now to get out my soldering gun and make a little box like dahenley linked to.