Marina Submersible Betta Heater

A pre-set submersible heater for very small aquariums, so a betta's water sits in the tropical range the fish actually needs rather than wherever the room happens to be.

Key features

• Bettas are tropical fish; in cool, unheated water they turn sluggish, eat poorly and are far more prone to illness
• Pre-set operation, with no dial to be knocked out of adjustment
• Polymer body instead of a glass sleeve, which stands up to knocks better
• Indicator light shows when the heater is drawing power
• Suction cup holds it flat against the aquarium wall

Specifications

• 8 watts
• Rated for aquariums up to 5 L (1.5 US gal)

Check that rating against your actual tank volume before buying — this is a nano heater, and a larger betta tank needs a heater sized to its litres. Keep it fully submerged where the water moves, and hang a separate thermometer at the far end, because a heater's own setting is not a measurement. Live bettas are in our Betta collection.