Best 15 gal Aquarium Heaters of 2025

The Fluval M50 Submersible Aquarium Heater is a top-quality heater suitable for use in freshwater and marine aquariums up to 15 gallons. It features a computer-calibrated thermostat and an easy-to-adjust temperature control dial, making it easy to maintain the desired temperature for your fish. Additionally, its shock-resistant Borosilicate glass and high-density ceramic heat sick make it a durable and long-lasting option that is easy to install with its slim profile tube for easy placement. The built-in reflective technology helps maintain the aquarium's natural look as the heater reflects the colors of the surroundings. Overall, the Fluval M50 Submersible Aquarium Heater is an exceptional choice for any fish owner looking for a reliable and efficient heater for their aquarium.

The Tetra Submersible Aquarium Heater is a versatile and reliable heater designed for aquariums between 10 to 30 gallons. It features an electronic thermostat that automatically maintains the water temperature at 78°F, which is ideal for most tropical fish. The indicator lights on the heater inform you when it's heating (red) and when the desired temperature has been reached (green). The heater can be installed vertically or horizontally, and its small footprint allows for easy concealment behind plants or décor. With its submersible design, it provides convenience and peace of mind. Simply place it inside your aquarium and plug it in after reading the label instructions. Enjoy a perfectly heated environment for your aquatic pets.

The Fluval P50 Submersible Aquarium Heater is a reliable and efficient option for aquarium enthusiasts. Its strong shatterproof polymer construction ensures the safety of both the tank and its inhabitants. With a preset temperature, there is no need for constant adjustment, making it convenient for users. The fully submersible design allows for easy positioning inside the aquarium, and the LED running lamp indicates when the heater is in use. Suitable for both freshwater and saltwater aquariums, the Fluval P50 Heater is a versatile choice that provides peace of mind and maintains the ideal temperature for your aquatic pets.

Keep your fish warm and happy this winter with the DaToo Aquarium Heater. This submersible heater features accurate electronic temperature control, ensuring a stable and precise water temperature for your beloved fish. With a simple turn of the knob, you can easily set the desired temperature (range 63℉~89℉) and the heater will automatically maintain it. The durable borosilicate glass shell and nickel-chromium alloy heating wire provide excellent thermal conductivity and uniform heat distribution, creating a cozy environment for your fish. The 6ft power cord allows for flexible placement, and with a one-year warranty, you can purchase with confidence. Let your fish enjoy a warm and comfortable winter with the DaToo Aquarium Heater!

The FREESEA Aquarium Heater is a 75W mini submersible water heater with digital temperature display and adjustable external controller. It is suitable for use in 5-15 gallon betta fish, turtle tanks and aquariums. The external controller can be mounted on the outside edge of the tank making it convenient to adjust temperature that ranges from 63℉ to 94℉. The double safety protection feature ensures the heater auto shuts off when the top part is out of water and stops heating when the actual water temperature is higher than 94°F. The digital LED temperature display shows real-time temperature and error code on the screen.

The Orlushy Submersible Aquarium Heater is a versatile 100W heater suitable for 10 to 20 gallons aquariums. It features a precise temperature dial from 68 to 89°F, allowing for complete control of aquatic climate within a 1-degree difference. The heater is made of 2mm thickened quartz glass making it explosion-proof and easy to hide in the tank. The sensitive and reliable thermostat maintains uniform temperature, and the heater automatically shuts off when the temperature is reached.

The HITOP 50W Aquarium Heater is a great choice for small fish tanks up to 15 gallons. The 2mm thickened quartz glass is much safer for both you and your fish. With an adjustable temperature range of 68 ~ 93 °F, this fish tank heater will automatically turn on or off to keep the water at the set temperature, and comes with an accurate sticker thermometer to detect water temperature at any time. Installation is a breeze with the two powerful suction cups, and an extra suction cup is provided for spare. Plus, the 12-month warranty provides extra peace of mind.

HITOP Mini Submersible Aquarium Heater - 50W is a small-sized heater suitable for seawater and freshwater heating for small fish tanks or fish bowls ranging from 5-15 gallons. It is easy to operate with a 6ft long cable wire and external temperature controller, allowing you to set the temperature between 68-93℉. The controller has a Digital LED temperature display that shows the real-time water temperature and set temperature, making it easy to read. Additionally, this heater has a fish-friendly design made of thickened quartz glass with good sealing performance to prevent water from entering.