My Ato runs flawless. I picked up a quality switch with 2 floats. When the water level drops a bit, the first switch turns on the pump and pumps kalk to the tank. The second switch over-rides the first and shuts down the ATO pump if the water level in the sump drops half an inch. This way I don't poison my tank. I also hooked up a light to the system. When the ATO pump turns on, so does the light. Makes it easy to tell if the pump is on.