[mike31154]

There is hardware available (solenoid) that is able to shut off your main water supply to the house. It may be wired to a water detector to automatically do its thing when water is detected. Kind of like a water alarm, but with the ability to take action rather than just make noise to alert you. Something like this has the potential to lower your home insurance rate. I'm somewhat baffled that these things are not actually required by code for new buildings these days.

As for a timer to shut off your RODI via a solenoid, that's pretty much the same thing, but you're still relying on the timer not to fail. 99.99% of the time this will work, probably for many years. But remember Murphy's law..... Having said that, I use a timer to run an air pump which pressurizes my ATO container. This in turn pushes water through a mechanical float valve into my display. I think I mentioned I don't have a sump, so this is the best scenario I could come up with, involving minimum risk of a failure. 3 components with potential failure modes, the timer, the air pump, the mechanical float valve. I suppose you can take that to the nth degree & include the container & tubing to the mix, but the likelihood of any kind of major disaster due to those is too minimal to worry IMO. Over the years I've come to know how long the timer needs to run in order to keep the ATO container pressurized sufficiently to keep up with evaporation. The beauty of this set up is that even if the air pump runs longer than it needs to, the mechanical float valve prevents overfilling the display. This has worked great for me for many years with only a few 'close' calls due to issues with the float valve.