Rated for a 5 or 10 gallon tank
| Model | Rated for | Power | Length |
|---|---|---|---|
| hygger Precise Aquarium Heater 50W Adjustable, electronic · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | 5–10 gal | 50 W | 5.9 in |
| Tetra HT10 Preset · sized for 5 gal and 10 gal Preset to 78 °F, inside the 76 to 82 °F a betta needs, with nothing to set. | 2–10 gal | 50 W | Not published |
| hygger Digital Mini Heater 50W Adjustable, electronic · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | 0.4–11.9 gal | 50 W | Not published |
| Fluval M50 Adjustable submersible · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 15 gal | 50 W | 11 in |
| hygger Titanium Tube Heater 50W Adjustable, electronic · sized for 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | 10–15 gal | 50 W | 7.09 in |
| EHEIM thermocontrol 50 Adjustable submersible · sized for 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | 6.6–15.8 gal | 50 W | 9.6 in |
| hygger Digital Mini Heater 75W Adjustable, electronic · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | 0.4–15.9 gal | 75 W | Not published |
| Aqueon Preset Heater 50 W Preset · sized for 5 gal and 10 gal Preset to 78 °F, inside the 76 to 82 °F a betta needs, with nothing to set. | Up to 20 gal | 50 W | Not published |
| Aqueon Pro 50 Adjustable, electronic · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 20 gal | 50 W | 9 in |
| Aqueon Submersible Glass Heater 50 W Adjustable submersible · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 20 gal | 50 W | 8.75 in |
| hygger Precise Aquarium Heater 100W Adjustable, electronic · sized for 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | 10–20 gal | 100 W | 5.9 in |
| Cobalt Aquatics Neo-Therm Pro 100W Adjustable, electronic · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 29 gal | 100 W | 9.75 in |
| Aqueon Preset Heater 100 W Preset · sized for 5 gal and 10 gal Preset to 78 °F, inside the 76 to 82 °F a betta needs, with nothing to set. | Up to 30 gal | 100 W | Not published |
| Fluval E100 Adjustable, electronic · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 30 gal | 100 W | 11.75 in |
| Fluval M100 Adjustable submersible · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 30 gal | 100 W | 11 in |
| Tetra HT30 Preset · sized for 10 gal Preset to 78 °F, inside the 76 to 82 °F a betta needs, with nothing to set. | 10–30 gal | 100 W | Not published |
| Aqueon Submersible Glass Heater 100 W Adjustable submersible · sized for 5 gal and 10 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. | Up to 40 gal | 100 W | 10.325 in |
| hygger Digital Mini Heater 25W Adjustable, electronic · sized for 5 gal Adjustable: set it between 76 and 82 °F and check the water with a thermometer. In a 5 gallon tank: Its 25 W is under the 50 W both charts give, so it may not hold 78 °F unless the room stays warmer than 70 °F. | 0.4–5.3 gal | 25 W | Not published |
| Aqueon Aquatic Flat Heater 15 W Flat · sized for 5 gal and 10 gal No temperature to set: it adds up to 6 °F to the room, so a betta’s 76 °F needs a room of 70 °F or warmer, day and night. | 5–10 gal | 15 W | Not published |
Before you choose
Put the heater where the filter’s flow passes it and check the water with a separate thermometer: a betta tank that drifts below 76 °F leaves the fish sluggish and open to disease. In a colder room, or a tank without a lid, work out your own figure in the heater size calculator. Betta care · How to size and place a heater.