Heaters & Chillers

Aquarium heaters keep tropical tanks at a steady temperature, and chillers cool tanks that run warm. Our articles compare models on published specifications and owner feedback, and say plainly who should look elsewhere. Heaters are electrical equipment, so follow the manufacturer's instructions and contact the maker if a unit behaves oddly.

Match a heater to your tank volume using the maker's own sizing guidance, and keep a separate thermometer so you can see what the water is really doing.

Start with our aquarium heaters roundup, or read the Fluval heater review for a single model in detail.