Shut off valves for RO DI unit? Before or after?

[theedudenator]

I ordered my RO DI unit.
I also bought a float valve for auto top offs...

I plan on putting in some inline valves on the water line, as I don't trust the float valve.

Should I position the vavle to cut the pressure before the RO DI unit?
Or should I have the valve after the unit, to keep the unit under pressure.

Figure someone here might have looked this one up

 

[lando]

I would have it before. This way your unit is not under constant pressure. This is how mine is set up.

 

[Todd]

I have looked into this myself. Right now, I use a Kent float valve on a trash can to fill up for water changes. That valve requires you to drill a hole to slide through. That doesn't work so well when your sump is 30 gallon aquarium.

So what I think I have come up with is the unit from autotopoff.com. It uses a slide float valve that hangs on the side of the sump. You then hook a solenoid to that to shut the water off before the RO/DI.

Is that what you use Lando? Because my 150 gal. evaporation is crazy. I would like a no-hassle setup.