Non-electric auto-topoff for ro system

[luckycat]

At some point I read something on-line about a float switch (non-electric) that simply opened/shut a valve to let in additional [acronym:6f6dcebca1="Reverse osmosis"]RO[/acronym:6f6dcebca1] water from an [acronym:6f6dcebca1="Reverse osmosis"]RO[/acronym:6f6dcebca1] tank when water levels fell below a certain threshold. This was not the same as running some pump...I have an [acronym:6f6dcebca1="Reverse osmosis"]RO[/acronym:6f6dcebca1] with a tank that I currently turn on/off in my sump (ball valve) to do a top-off... the switch I saw was something like the valve in a toilet that has a ball on it that raises/lowers to operate the switch.

Anyone use a mechanism like this for their auto top off? Or know where I can get one of these?

They work OK, but just make sure to keep it clean cuz sometimes they get stuck in the "fill" position...

[luckycat]

I was doing a search and found Kent Float Vales, which I think is what I'm looking for...but to avoid this "sticking"problem or at least reduce likelyhood of the problem can I put two in series, one lower than the other? So both would need to stick to have a problem.

[indy]

The output for the valve is a small hole behind the float. I can't think of any way to feed one into another. I've got one in my sump and it works ok, sometimes better than others. I'm planning on putting a sprinkler timer on the input to the [acronym:2930b878e8="Reverse osmosis"]RO[/acronym:2930b878e8] unit so it can only possibly run an hour a day, just to be on the safe side.