You won't hear much from me for automation. CaRx is the most automation that I will use - it would take a month for it to mess up a tank if it stopped working or was generating too much output, and since I check alk at least every other day, it is easy to catch. I don't even use a ATO, I turn a ball valve above the tank and wait there for 10-15 seconds while the tank fills and then turn it back off. There are two types of ATO, IMO... those that have failed and those that will, but at least most of them fail "off" now, which is good. I always argue to automate nothing - lamp/light timers and CaRx is enough for me. I just don't trust hobby-grade sensors, floats, etc. I also find that taking a look at least once a day will also keep me more in tune to what my tank needs.