Ball valves for us - I’ve used off-the-shelf agricultural valves and a little wooden mount (for now - want to replace them with something more robust) with a solenoid and rod to open and shut them. Means I can also just do it manually if I want to. So far, so good, and if something fails open, I’ve an alarm set in openhab if there’s an unexpected delta in tank levels. Hasn’t happened yet, and losing all of our water isn’t too big a deal in winter - that’s happened a few times due to burst pipes, as it’s brutally cold here at the moment, and I haven’t buried everything yet - hundreds of meters over inhospitable terrain. We’re at 7 bar - 70 meters - so when something goes, oh boy does it go.

Fruit fly control - nothing. We’ve enough that we can share with the bugs and the birds, although fruit flies don’t seem to be a problem for us, as I think they’re getting parasitised by native ophid wasps. We also don’t have too many of the same type of tree near each other, which likely also helps inhibit pest spread.