I got a 40b with Auto Aqua AWC/ATO and this is the 2nd time for whatever reason it has stuck on during the Auto Top off Stage. The first time I was here and caught it and thought maybe I had it set up wrong. It was when I first got it. Today I got home and found out that it stuck open and overfilled my tank. I got a 2, 50g Brute's that I use for AWC and ATO. Well, the ATO can was empty and I filled it last Sunday. It usually lasts over a month. 50g of freshwater drove my salinity from 1.026 to 1.015... No fish died but a few corals look in real bad shape, a few acros are already all white, a few others are about half and half... guess I just wanted to vent as it sucks. Of the 40-50 or so gallons of water on the floor, it only got about 10 feet of the carpet before it used the slope of the concrete to find the floor drain in by the furnace and washer machine. I'm more ticked or saddened about the corals that the flooded floor. I had just got this green one to start taking off, for the last 6 months it had only grown about a 1/4 of an inch then this last month or so it had tripled in size... god I love and hate this hobby at the same time.