So earlier in the day I heard a strange air sucking sound coming from one of my gurgle busters. I made a mental note to check it when I had a minute but I got busy with work. I just walked past my tank and noticed that the water in the display was rising over the overflow boxes and about to the touch my screen tops! Just shut down the pump. Looks like I have a lot of snails hanging out in the overflow boxes. I'm wondering if they managed to get into the narrow openings of the gurgle busters??? Not happy right now!