sensor

Trying to find a couple cheap water bugs to use with the breakout box..... found my float switches.... but i don't want the water to get that high before i know, if you know what i mean....

Hi , just trying to buy an auto top off , but confronted with some problem about one. I've tryed the one with optic sensor and it didn't work. Suppose to be the best , better than floaters, what do you think. Floaters or optic sensors for you. For your info, optic sensor don't work near other...