Help with AquaFX RODI Unit

[BlueTang<3]

This may not help much but my new system is about 550 gallons so far and have 2 90 gallon poly tubs that I run with float valves. I have always used the vertex 100 gpd rodi units it allows me to turn it on and once its full the vertex has pressure sensors that turn off the unit. I also run water on the floor sensors as a backup if it failed but havnt had an issue yet been doing it like that for 3 years with my old system. But I also plan kn changing 90 gallons bi weekly, nothing worse than waiting for water or in emergency so that's why I have 2 tubs but they are cumbersome and take up a lot of space.