Even Big Als orders arrive one day, and as soon as I got the float valve, I thought about ways to attach it to my tank. Drilling a big hole into one of the sides wasn't an option, so I drilled some holes into the tank rim and the valve itself, and connected the two as shown.
Interestingly, it seems like the way I attached it gives me a perfect level in the tank... without further adjustments. This kind of dumb luck always worries me. There is a tiny leak between the black and white connectors, which I can fix with some pipe tape around the threads or let it drip as another way of auto topoff.
Can't wait for my next waterchange!!!