I finally got around to setting up my RODI system properly, more or less.
Now I have a boost pump, which brought down the TDS a little and really improved the production rate. There is a float switch on the collection bin, and a pressure switch on the fill line to shut the pump off when the float switch closes.
My only remaining modification is to put a 3/8" line in the bin just above the float switch, and plumb it to a "T" in the drain line, just in case the float switch fails. Luckily I'm able to do this since my drain is lower than my water bin.
Everybody has a DI water flood one ow twice. But, DI water doesn't really stain anything and is nowhere near as much of a mess as saltwater.