Best Mini Aquarium Heaters

Orlushy 25W Small Submersible Aquarium Heater, Constant Temperature Betta Fish Tank Heater of 78℉for 1-6 Gallons Freshwater & Saltwater Tanks

Tetra HT Submersible Aquarium Heater With Electronic Thermostat, 50-Watt, 2-10 Gallon

PULACO 25W Small Aquarium Submersible Betta Heater with Free Thermometer Strip, Under 6 Gallon Fish Tanks (Preset Temperature 78℉)

DaToo Mini Aquarium Heater 25W Small Fish Tank Heater 25 Watt with Free Thermometer Sticker

AquaMiracle

AquaMiracle Adjustable 30W Small Aquarium Heater Submersible Fish Tank Heater Betta Heater Turtle Heater Super Mini Aquarium Heater with Digital Display Thermostat, for 4-6 Gallon Tanks

YukiHalu Small Submersible Aquarium Heater, Adjustable Mini Fish Tank Heater 25W 50W 100W 200W 300W with External Temperature Controller, LED Display, Used for 5/10/20/40/60 Gallons (25 Watts)

AquaMiracle

AquaMiracle Adjustable 10W Betta Heater Small Aquarium Heater Submersible Fish Tank Heater 5V/2A USB Powered Super Mini Aquarium Heater with Digital Display Thermostat, for up to 1 Gallon Tanks

hygger Small Aquarium Betta Heater, Submersible Fish Tahk Heater 10W/25W/50W/100W with LED Digital Display, Suitable for Marine Saltwater and Freshwater up to 5/10/16/26 Gallon

YukiHalu Small Submersible Aquarium Heater, Adjustable Mini Fish Tank Heater 25W 50W 100W 200W 300W with External Temperature Controller, LED Display, Used for 5/10/20/40/60 Gallons (50 Watts)

FREESEA Aquarium Fish Tank Heater: 50W Small Submersible Turtle Heater with Adjustable Temperature External Controller for Betta | Saltwater | Freshwater | 1-10 Gallon