Review on MarineLand Precision Heater: Optimal Temperature Control for Saltwater and Freshwater Aquariums by Jasmine Harris

The heater seemed great at first and I gave it five stars initially. I'm changing that now. I have the heater less than 3 months old and it's not great. The thermostat setting is no longer accurate. I should set them 2-4 degrees higher than the actual temperature I want my aquarium to have. When I first put it in the tank it heated up surprisingly quickly, which is what I was expecting from a 300w heater. Now it's taking forever. I did a 50% water change yesterday so apparently I turned the heater off so it wouldn't run without water. In any case, I screwed up a bit, which caused the water temperature to drop to 72 degrees. My thermometer is set at 80 to keep 76-78 degrees. After changing the water, I reconnected the heater. Still set at 80, it heated the water from 72 to 72.6 and then shut off. I gave it ten minutes and it still wouldn't turn on so I had to turn it up and down to turn the heat back on. It heated the water to about 74 and then started working again. I had to manually turn the heat on twice more in the TWO HOURS it took to increase the temperature from 74 to 78. It seems to be keeping the temperature fairly even at the moment, but I've ordered another one. Heating. I may have just gotten a lemon, but I wouldn't risk getting another one.