Review on MarineLand Precision Heater: Optimal Temperature Control for Saltwater and Freshwater Aquariums by Janet Scollins

I unpacked this heater and placed it in a 5 gallon bucket filled with water to test it out. I waited 30 minutes to turn the unit on and when I did the light came on to indicate it was heating up. After about 3 hours the temperature was 80 degrees even though the thermostat was set to 77 degrees. I have a heater control that turns off the power when the temperature hits 82 degrees, so I figured no problem, I'll use it anyway. In just 2 days I did a 50% water change and the temperature dropped to 75 degrees. The heater was set to 77 degrees so I gave her a few hours to warm up while I ran some errands. When I got home, our water was 82 degrees! What the hell! I turned the thermostat on the manifold to 75 degrees and the heater light stayed on for over 3 minutes so I just turned it off. I will definitely be returning this unreliable junk. DO NOT TRUST THIS HEATER! He will cook all your fish! I bought it because I thought Marineland was a reputable brand and it was the cheapest option, but it ends up being the most expensive option if it kills all your fish!