Timer for RO line

[Stacey Keyes]

Hi

I have an existing RO filter with a 14 gallon reserve tank that I use for drinking water as well as my aquarium. I bought a 75 gallon RubberMaid container that I want to keep filled for use during water changes. My problem is that I can drain my 14 gallon RO tank in 20 minutes and then I don't have any drinking water left. What I am trying to find is some sort of timer for my RO line that will only allow it to fill my large reserve container for 10 minutes a day so I dont use all of my RO water at once. Then, when the reserve container is full, a float switch will shut off the RO line completely. I've searched the web for a timer for an RO line but cant find one. Has anyone heard of such a device or have any other ideas to accomplish what I want to do?

 

[AZDesertRat]

You never want to use a pressure/drinking water tank for reef water. The cycling on and off to satisfy the pressure in the bladder tank leads to TDS creep which is not good for the reef or especially for DI resin which I hope you are using since RO only gets you 90-98% of the way to where you need to be. RO acts as pretreatment for DI.
What you are trying to accomplish is very easy and done all the time as shown in this diagram:
http://spectrapure.com/huds/4-STAGE-DWK-RODI-NAG.pdf

Note in the diagram there is a 1/4" check valve between the RO pressure tank used for drinking water and the DI. This allows you to have pressurized drinking water at all times and when a simple float valve, not even a float switch and solenoid valve drops and calls for water the Autshutoff Valve (ASOV) on the RO opens and makes water until the float valve is in the raised position and shuts it off. The Rubbermaid or whatever fills directly from the membrane and not stored water so TDS creep is minimized. If you are not using DI I would strongly recommend doing so as shown in the diagram so you have reef safe water. It is simple to add an add on DI and it does not affect the drinking water.

One thing I would suggest though is to shut the reef water fill off once the storage is full and let it drop at least 10 gallons before opening it back up again so the float valve does not make the RO kick on and off frequently which gets you back in the TDS creep situation. I use two float switches placed 12" apart and a solenoid valve for just this reason, in my 23 gallon Rubbermaid it calculates out to 11 gallons before it starts again to refill.

 

[Stacey Keyes]

Great info, thanks. This is what I will do

 

[Tautog]

For what it's worth............when I started, I used the LFS saltwater, about 25 containers that I saved. I'm new, so I do everything manual. In between water changes, I go thru 10-12 containers. I make water for a water change, 30 gal, then re-fill these small containers for evaporation. I always have about 50 gal. on hand, just in case. The best thing is the containers only weigh 35 lbs. and are easy to carry.

 

[AZDesertRat]

I do much the same. I keep 50+ gallons of RO/DI around all the time, 23 in the Rubbermaid ATO container and another 25-30 in 5G drinking water jugs or the blue cube style camping water totes.