How to plumb the RO/DI water to an automatic Top off?

[Sambo]

This could be another very basic plumbing question...

I've seen people talk about plumbing the RO water for topping off directly into the sump, regulated by a float valve. How? What fittings would I need to hook my blue water line (can't remember the diameter - 1/4"? 1/2"?) up to a float valve? (and what sort should I buy?) Next question - does it matter that the RO filter is at the other end of the basement (ie approx 20 feet away) or should I replumb the filter?

cheers

sambo

[Geoff]

first you need to make sure your RO/DI filter has an ASOV (auto-shut off valve) on it. this keeps the waste water from continuously running while the float valve is blocking new water from going into the system.

i have a 3 way backup system. i have a float switch that actually controls the water level in the tank. this consists of a float switch, a transformer, and a RainBird 3/4" sprinkler soleniod. if this were to fail than i have a Kent Float valve on the end of the line going into the sump. if this were to fail i have a water sensing shutoff valve that will cut off the water supply before the RO/DI filter.

so far it has been working fine.

G~

[Sambo]

I like the built-in redundancy! So (sorry to be so dense) - the rainbird solenoid is the electrically operated valve? And where did you get it? (did you have to modify the fitting to take the hose from your RO unit??)

sambo

[Geoff]

i got my soleniod from Home Depot. they are in the sprinkler aisle. they are about $15. i actually have two on my system one for the auto top off the other for the semi-auto Water Change system.

i got the threaded versions. it took me about half an hour in the plumbing aisle before i found the minimum amount of connectors necessry to go from the 3/4" solenoid to the 1/4" Guess fitting.

G~

[Sambo]

And now have just found the Kent float valve on the marine depot site (I kept finding float switches that were designed to operate pumps rather than gravity-fed)

Thanks for the help (again again)

[Geoff]

those float switches that are designed for operating pumps can also be used for operating the sprinkler valves.

G~