Okay so I need some help. This is about my 125 gallon I noticed many fish have died and I am now in a mini cycle (completely unrelated :;soldier) but I have been noticing for the past couple months that my tank has been in the 80s. I have two heaters due to the fact that when I set it up originally I couldn't keep it warm enough. This actually started happening more recently. I started noticing it after I added an air pump to the tank. I have the air pump directly under one heater, so the bubbles come up around the heater. I have been turning both heaters down waiting a week or two and checking again. Nothing will change. I now have both of them all the way down and my tank is still 84 degrees. I thought about it today and the one seems like its never one (it has a light to let you know when its on) so I think it kicked off since the water is over what I have it set at. But then the other heater which has the bubbles coming around it was still warm to touch. So that one is still heating the water. I have it turned all the way down but its still heating it. So I thought today....the air pump could be causing the heater to think the water is actually as cold as the air coming around it. The air in the room the tank is in is quite cold. (Its the basement) so then its pushing the cold air through and so I would think that could be why? What do you think? I plan on moving it to help but I am worried maybe the heater itself could be bad? I really want to know what you think so it stops stressing my fish.