A small fish tank heater is good for tanks with a volume up to 10 gallons.
It is important to provide the right requirements for your fish to survive and thrive. Not having the correct water temperature can cause great stress to your fish leading to a shorter life span. If the conditions are not optimal, wrong water temperature can easily lead to death if not quickly remedied.
I lost one of my favorite fish a couple of years ago because my aquarium heater became unplugged and I did not notice. You read about my beloved Little Moe in this Fish Tank Thermometer article.
But let’s get into what you came here for: the best small fish tank heaters.
The Best Small Fish Tank Heater
Here are a few basic pointers to keep in mind when thinking about small tank heaters.
Important to remember:
Only turn an aquarium heater on once it has been placed into the water
Get a covered fish tank, or make a cover for your tank to help trap the heat in – it can be hard to reach and maintain temperature with an open tank
If you need to remove a heater from the water, switch it off and let it cool for a while before removing it from the water
Let’s see the recommendations.
1. Tetra HT Submersible Aquarium Heater With Electronic Thermostat
The Tetra HT Submersible Aquarium Heater is the best small fish tank heater. It can be purchased in either 50 watt (model HT10) or 100 watt (model HT20). Both options are best used for tanks with a volume of between 2 and 10 gallons.
Your choice of model will depend on factors such as the ambient temperature in your house and the size of your tank. If you live in a cold climate, keep your house rather cool, and have a 10 gallon tank, you should consider getting the 100 watt model. But for most other scenarios the 50 watt heater will be the perfect choice.
This is a small water heater which can be easily concealed behind your tank decorations and plants. The 50 watt model is approximately 5 inches long, while the 100 watt model is just over 8 inches long.
Features of the Tetra heater:
This is a fully submersible fish tank heater that is attached with a suction cup to the inside of the tank
It can be installed vertically, diagonally, or horizontally – as long as it is under water it will function
Lights to indicate when the heater is reaching temperature (red) and when water has reached the set temperature (green)
Automatically set to heat to 78° F with an in-built electronic thermostat – the temperature cannot be changed
Automatic shut-off feature in the event of an electrical short
2. Uniclife Submersible Aquarium Heater 25-50W with Thermometer
The Uniclife Submersible Aquarium Heater is an adjustable heater with a thermometer. The temperature can be set between 61°F and 90°F (or 16°C and 32°C). Most aquarium fish need a water temperature of between 76°F and 80°F. Check out some more specific temperatures for different fish down below.
This heater comes in two models – a 25 watt and a 50 watt. The 50 watt heater is going to be sufficient for the major majority of fish tanks up to 10 gallons. The 25 watt model is great for 5 gallons and less.
The thermometer that comes with this heater is a sticker. It can be peeled off and stuck onto the side of your fish tank.
Features of this small fish tank heater:
Made of shatterproof glass
Double insulated heater
Temperature dial on the top of the heater
Automatically switched on and off to stay at the correct temperature
Can be placed horizontally, vertically, and diagonally in the tank
The Marina Submersible is a very small Betta fish tank heater. This is only an 8 watt heater that is suitable for up to 1.5 gallons of water. This heater is always on and has no thermostat. It would be a good idea to get a thermometer to go with this small heater. As with most fish, Bettas prefer a tank temperature of 78 degrees.