Need help with sump/fuge

[TheReefGeek]

Can't tell much from the picture, but I don't think that will control your RODI unit.

If you want to run your RODI unit to float valves, you will have to rely on pressure in the line (created when the float valve closes) to trigger a diaphram in a hyraulic valve plumbed right into your RODI unit. It is actual the pressure difference on the two sides of the diaphram that triggers it to shut off water to the RODI, thus cutting off waste water production as well. BUT, if your line between the RODI and the float valve(s) is too long, you will have to install pressure bladders (check out spectrapure systems for an example of these) to create enough pressure to trigger the diaphram to flip.

The other way is to control it electronically with float valves. Very possible but I have had too many fail open to trust them anymore myself.