Float Valve?
 

Where can i get a float valve for an auto top off system?

I can't seem to find one.

Thank you

Home Depot sells float valves. All plastic ones made by "Wait" or something like that. Its for humidifiers.

http://www.jlaquatics.com/phpstore/s...ID=ro-kpfvalve

Are you trying to control and RODI until, or just water from a reservoire into your sump?

Here's my HomeDepot (might be Waite) humidifier valve hooked directly to the ro/di. Doubt the sump level varies 1/4" in total since installed (salt line you see is since from adding some extra fans).
http://i67.photobucket.com/albums/h316/das75/float.jpg

Humidifier valve connected to an RODI, can you explain this more?

How do you stop waste water production from the RODI?

Have the Aqua-safe with tank, float valve is hooked up to the ro/di output line. RO/DI unit works as normal, no demand (no flow), no waste water.

Grand plan was to have the ro/di unit feed a reservoir with aeration (for pH adjust and to limit possible amount of fresh water that might be added if float failed), reservoir supplying sump via float valve.

Thinking now this setup works great, don't need to worry about topping up a reservoir, only adding little ro/di water a time so doubt I'll get much pH swing (system volume ~200g) and really, how many people have ever flooded their basement because their humidifier float valve got stuck open?

But waste water production doesn't stop unless you stop the water supply to the RODI, how does your system control this?

Check if your unit is continually making waste water or not, even when the tank is not demanding water.

The RODI will stop waste water production if you have a hydraulic valve plumbed into the RODI that detects the pressure increase when the float valve closes, do you have this then?

I picked up an auto shut off float valve at Wai's. It was worth the $20.

My Aquasafe RO/DI has an auto shut off valve to stop the water flow.