??: Setting up ATO from RO/DI

[DEViSE]

So, for the longest, I've used the primitive way of an ATO. Pump on/off a few times a day based off evaporation. However, I'm looking to get techie and seeking a shopping list for having my rodi unit automatically fill a reservoir which in turn fills the sump. I currently have the SpectraPure 90gpd RODI unit, no pressurized tank. I turn it on, run the line to my ATO reservoir (7g food grade container), let it fill.. turn the RODI unit off. It's kind of annoying. So, I've a few questions.

I've looked at quite a few videos and browsed the forums, but nowhere seems to point out what the RODI unit does when the reservoir is full and the float valve has shut off the clean water line. Does it continue to run, simply pushing water out the drain line? If so, does this bypass the filters in the unit (thus, not wasting them? ..this seems like a waste of water, if so.) Or am I required to get a pressurized tank for this to work? This bit just confuses me.

If I gathered my info correctly, I would need to get a float valve for the reservoir and the ATO sensors for the sump. Plus whatever is required for the RODI to behave properly when no water is required. I have a couple of aqualifters sitting around. Is this all I would need?

If someone could be so kind to toss me a shopping list, that would be superb. I'm not looking for the poor man's approach, something dependable and lasting.

 

[Loki]

I would say the float switch is all you will need. Well that and the obvious line/fittings to get it to your top off tank.

Once the float switch is closed (when the tank is full) it will put pressure on the incoming water and your auto shot off valve in your RODI will stop the water flow. No need for a pressurized tank IMO. I am unsure of your design plan to know what kind of shopping list you will need. The your water pressure in the house will fill the tank and you should need any pumps either.

From what I have heard this will have a negative effect on your RODI membrane because it will only create small amounts of water and not truly flush the membrane out causing it to prematurely fail/need replacing.

 

[Loki]

Also I do not have mine setup like this. This is just how I would do it and how I think it will work. Maybe someone that has one like this will confirm what I said or call me names

 

[AZDesertRat]

You need an ASOV, autoshutoff valve. This shuts off both the treated water and the waste or brine flow when the solenoid shuts off or the float is raised.

Spectrapue has dozens of diagrams under their "Hook Up Diagrams" section on their main web page.

Personally I would never trust a float valve since I have seen way too many running toilets, evaporative coolers and swimming pool self levelers in my time. A solenoid valve with float switches provides a positive shut off. They have several options under the liquid level section on the same web page. I use the solenoid control on my 23 gallon Rubbermaid ATO container.

The sump uses a UPLC-II with a digital air pressure switch to control the sump and tank level and pulls from the ATO container in my garage 35 feet away.