Originally Posted by Betowess
Sergio, why do you need an electronic valve into the drain line, after the pump....
Also, that is a fairly spendy solenoid. What is the advantage? Is it more reliable than others...why did you opt for that particular unit? TIA and thanks for posting. Very informative.
The solenoid is there because the pump is not capable of stopping the forward flow of water to the drain line when it is off. If it wasn't there, the tank would be constantly draining because it is plumbed to the canister. I initially was going to drain directly from the tank via the pump, but then I'd have an issue with the siphon that would be started. I did come up with a solution for that, but opted to plumb to the canister so there was one less item in the tank.
I think the solenoid was overkill. My original justification was the 3/8" opening it provided. This prevents excessive back-pressure on the pump. Steve (scolley) pointed out that I could have run a few MUCH less expensive RO valves in parallel.
Don't tell my wife!