I am reaching out to the Reef2Reef community to see if anyone can help me. I currently just setup my 120 and I started using a Tunze 3155 Osmolator ATO that I had for about 3 years from the previous setup. When I installed the ATO the pump came on and filled the water to the sensor. 2 - 5 minutes later it would start to fill again adding about another 1 1/2 gallons of water and triggering the high alarm switch which activates the high alarm ( drives my wife crazy). Cleaning the sensor with vinegar did not help. After about a month of battling this problem I bought another one yesterday and set it up today. Unfortunately, it is doing the same thing with a new unit. I have even used my old bracket to set the high alarm switch at a higher level because the pump will not shut off at the sensor point, it just overfills completely submerging the sensor. I do not know what I am doing wrong but I don't remember having these issues before. If anyone has any recommendations on how I can solve this issue I would greatly appreciate it.