@Jeffcb I only had mine running a short time and after hearing all the negative comments about the stock ATO float I removed it. Replaced it with an Osmolator replaced that with an Apex ATK.Woke up in the middle of the night with the sump low and blowing air bubbles. Added a little top off water and went back to bed. Disassembled Red Sea float valve. It was full of some sort of slime. No telling what. My sump has all kinds of stuff living and growing in it. I even have several baby Trocus Snails. I guessed they are breeding. Soak it in vinagar and cleaned it well. Very simple to do.Works great now.