The Tetra Submersible Heater and Tetra HT Submersible Heater are designed to automatically heat up your fish tank water to a range of 76°F to 80°F (or 24.5°C to 26.5°C). If the device does not appear to be working as intended, or at all, then you can take a look at this troubleshooting article here at Aquarium Blueprints.
For this guide, we will be covering the following versions of this product:
- Tetra Submersible Heater for 2 to 15 Gallon Tanks (50 Watt)
- Tetra HT10 Submersible Heater (50 Watt)
- Tetra Submersible Heater for 10 to 30 Gallon Tanks (100 Watt)
- Tetra HT30 Submersible Heater (100 Watt)
- Tetra HT40 Submersible Heater (150 Watt)
- Tetra Submersible Heater for 30 to 60 Gallon Tanks (200 Watt)
1. For the first step, we recommend testing the temperature of your tank. When doing so, try to measure as far away as from the heater as possible so that you can get an accurate reading.
If the temperature is within the aforementioned range, then the heater should be working correctly as it will turn itself off once a minimum of 76°F (or 24.5°C) has been reached. It won’t turn itself on again until the temperature falls below the aforementioned temps.
2. If the tank water is colder than the intended range and the Tetra Submersible Heater isn’t turning on, then you can try re-positioning the device.
This product works best when it is placed in a horizontal or diagonal position. You should also place it as close to the bottom of the tank as possible so that it will heat up the aquarium more efficiently.
Furthermore, you should also put it near an area with high water flow (we put ours near an air stone, for example). By doing so, the heat will more easily spread across the tank water.
3. It is important to note that the Tetra Submersible Heater will only heat the aquarium up to a certain point. If the water is too cold to begin with, then you won’t be able to 76°F (or 24.5°C).
Similar heaters can only increase the temperature by 10°F (or 6°C) more than the room temperature. So, if your room is below 66°F (or 19°C), then you can try using a space heater to warm up the surrounding air first. Afterwards, you should see the temperature rise in your tank water as well.
4. If your heater is covered with algae or mulm, then you can try cleaning it by taking the following steps:
- Unplug the heater from the wall socket.
- Wait for 15 minutes for the device to cool down.
- Take the heater out of the tank water and then gently wipe the algae or mulm off.
- Put the device back into the tank water.
- Wait for another 15 minutes for the heater to adjust to the water temperature.
- Plug the heater back into the wall socket.
5. If none of the aforementioned potential fixes have helped, then you may need to get a new heater.
If your Tetra Submersible Heater is still covered under warranty then you can try contacting Tetra about potentially getting a replacement.