Review on Adjustable Float Valve Mounting Auto Water Filler Controller - Aquarium Auto-top-Off System Water Level Controller for Pet Supplies by Katie Harris

Definitely works fine. I took off a star because I had to attach the cabinet door's clear rubber bumper to the inside of the clamp so it would properly fit the rim of the 5 gallon bucket I used it on (to make RO/DI water) . ). However, when I did, everything was perfect! It's not too big, but in the aquarium it will still be irritating to the eyes. I STRONGLY RECOMMEND THAT THE MANUFACTURER TRY TO MAKE A BLACK VERSION OF THIS DEVICE. This would make it less visible in an aquarium.