Best Aquarium Heaters for Betta of 2025

The PULACO Small Aquarium Betta Heater is a 25W heater that is perfect for small aquariums up to 6 gallons. It has a preset temperature of 78℉ and is very easy to install vertically or horizontally. Once plugged in, the heater automatically controls the temperature and keeps it constant at 78℉. It is important to fully submerge the heater in water and to use a water pump or filter to circulate the water while heating. The product comes with a 12-month warranty and 24-hour professional after-sales service.

The AQUANEAT Betta Heater is perfect for small aquariums ranging from 3 to 5.5 gallons. Its compact size of just 4.5 inches ensures it won’t take up much space or block your view of the tank. This heater comes preset to 78°F, an ideal temperature for Betta fish and other tropical species, making it easy to use—just plug it in and enjoy. You can easily monitor its operation with the indicator light that shows red when heating and green when at rest, allowing quick daily checks to keep your fish comfortable.

The DaToo Mini Aquarium Heater 25W is designed to create and maintain a perfect and comfortable water temperature for small fish tanks of 1 to 5 gallons. With precise and constant temperature, it keeps the temperature of the fish habitat in the best state at all times. It is the smallest 25W aquarium heater on the market, ensuring that it can fit perfectly in any small fish tank. Made of quartz glass material, this heater is explosion-proof and crack-proof, making it more sturdy and durable. It also comes with a one-year warranty and satisfaction guarantee.

The DaToo Mini Heater is an ideal solution for those with small aquariums. Its compact size, similar to your thumb, allows it to fit seamlessly in tanks up to 2 gallons, ensuring your fish have a cozy environment. Thanks to its PTC ceramic heating technology, it can quickly adjust the water temperature, keeping it stable and safe for your aquatic pets. The durable PVC protective shell makes it resistant to impacts and corrosion, enhancing its longevity. Plus, with easy installation—just submerge and plug in—you'll have a warm aquarium in no time.

The Orlushy 25W Submersible Aquarium Heater is perfect for tanks between 1-6 gallons. Its compact size, durable materials, and easy-to-use features make it a great addition to your freshwater or saltwater tank. The automatic constant temperature heating system keeps your tank at a comfortable 78℉, and the stair shape heating technology saves energy and electricity. The ABS material outer shell and nickel-chromium heating wire provide safe and reliable operation, and the non-corrosive quartz glass ensures faster heating rates.

The hygger Mini Heater is designed for small aquariums, making it perfect for your Betta or turtle tank. With its safety features, including a beep alarm and automatic shutdown during malfunctions, you can feel secure knowing your fish are safe. The adjustable temperature control allows you to easily set the water temperature between 59 and 93 degrees, ensuring your aquatic pets stay comfortable. Plus, the heater maintains a steady temperature automatically, so you don’t have to worry about constant monitoring. Its compact size makes it easy to hide, providing a clean look in your tank.

The FREESEA 50W Heater is a versatile aquarium heater suitable for 1-10 gallon tanks. It features double safety protection, automatically shutting off when out of water and activating overheating protection. The external controller allows easy temperature adjustment from 63℉ to 94℉, with a LED display showing real-time temperature. The 5ft power cord provides convenience for indoor use. With a 12-month warranty, this heater ensures peace of mind for betta, saltwater, or freshwater tank owners.

The VCRAZE Mini Heater is a compact solution for heating small fish tanks. Its tiny size, about the length of your thumb, makes it perfect for nano and betta tanks. With advanced technology, it maintains a precise temperature within 1°F, ensuring your fish are comfortable. You’ll appreciate the ultra-safe 5V/2A USB power source, which reduces electric shock risks. Plus, the overheating safeguard automatically shuts off the heater if water temperatures exceed 97°F, giving you peace of mind while caring for your aquatic pets.

The hygger Aquarium Heater offers excellent features for maintaining optimal temperatures in small fish tanks. With a temperature range of 59-93°F, this 10W heater is perfect for aquariums up to 5 gallons, ensuring your fish and turtles thrive. Constructed from durable quartz glass, it resists breakage and corrosion while protecting your aquatic pets from burns. The built-in protection against overheating and dry running provides peace of mind by stopping heat when temperatures rise too high or water levels drop. Its compact design takes up minimal space, making it ideal for nano tanks while delivering powerful performance.

The AquaMiracle Betta Heater is a super mini aquarium heater that is perfect for nano tanks and betta tanks. With its innovative thumb-size design, it takes up very little space and is easy to hide. Despite its small size, this heater packs a punch with a temperature range of 64-93F, suitable for tanks up to 1 gallon. Powered by a 5V/2A USB power supply, it eliminates the risk of electric shock and can be used with a power adapter or power bank. The intelligent inverter technology ensures accurate temperature control with a 1F accuracy, making it more reliable than traditional knob-controlled heaters. It also features overheating protection, so you never have to worry about "cooking" your fish. In addition to aquariums, this versatile heater can be used for turtles, pet fountains, and plant seedlings.