I have been using the Fennix heater controller for my Fluval m300. Nothing but great things. I set it at 78F and i have never seen my temp drop below 77 nor go above 78F. I found it on amazon.com for $30. Check it out. I still need to buy another one for my 240 gallon.I'm looking to try out a temperature controller. I'm tired of playing around with my heaters to get the desired temp. Can anybody recommend a good/reliable one? I was thinking about getting one from Jehmco. Advice?