I'm currently working on getting mine set up along with a Neptune DOS so I can run continuous water changes. It will also server as my ATO. Hopefully the days of lugging 5g buckets up and down the steps are gone.
The RODI tank (on the right) has two float switches. The bottom switch will open a solenoid that controls the RODI system feed from the tap. The top switch will close the solenoid. In the event that it doesn't, the RODI feed is attached to a BRS float switch that will manually turn off the system.
The NSW tank only has a low float switch for now which will disable the DOS until I can transfer water from the RODI tank and mix the salt.
I've piped the drain from both the DOS and the RODI into the side of the sink, so no worries about flooding the basement from those lines. I'm also planning on leak detection sensors for the Neptune.
I ran a CAT 6 (solid core) line from the float switches to the BoB that's under the tank. It seemed like an easy way to get enough wire for 4 switches and they are even color coded.
I also ran lines for the ATO feed, DOS feed and DOS drain.
I spent more than I should so it looked pretty. I'm going to be the only one that ever sees it, but it makes me happy.
Now all I have to do is figure out how to program the Apex. I've used it for a few years, but only for the basics. I'm completely lost when it comes to any of the higher level stuff, like virtual outlets, Defer, OSC, etc.
Anyway, here are a few pictures.