Review on Mini Fluval Marina Submersible Aquarium Heater: Effective Heating Solution for Fish Tanks by Jessica Silva

I bought this heater for my Betta to replace a previous one that was not keeping the water temperature stable. My rooster lives in a 7 gallon bubble bowl filtered with a Lustar foam filter. The compact size of this unit and the ability to regulate the water temperature was just what I needed and I was so pleased with the constant tropical warmth it provides. I have read many reviews of this heater, some of which have been inaccurate. People need to know two things about Marina Fluval's immersion heater: #1 it's fully submersible. The "waterline" mentioned in the description indicates the minimum depth to be respected, not the maximum. #2 Even if there is no specific temperature (like 75°j markings other than top and bottom) you know there is a thermostat! To set the temperature, you need an aquarium thermometer. First set up an aquarium with no fish. Heater and wait a few hours. The display will turn off when the default temperature setting is reached. I had 78 degrees. If you want the temperature to be warmer or colder, turn the knob up or down to the mark. After a few hours, check the thermometer again. If you see that the water temperature is correct for a few more hours, the heater is set correctly - it automatically maintains the water temperature in your aquarium.