Hydor Aquarium Heaters
Hydor aquarium heaters take a revolutionary approach with these two product lines. ETH in-line heaters install in your canister filter or sump, remaining outside your tank and heating your water evenly. THEO submersible heaters feature shatterproof design and advanced heating technology. And Hydor's Mini Heater is a fully submersible heater perfect for small tanks and fish bowls.