The ETH External Thermal Heater from Hydor offers peace of mind when heating your aquarium, with its unique PTC (Positive Therma Coefficient) system. Unlike other standard heaters, the ETH External Thermal Heater is not placed in the aquarium, but instead it is attached to the external filter. The heater is easily mounted on all external filters and heats your aquarium water safely and precisely.
This item has been discontinued. We apologize for any inconvenience. Hydor Theo Aquarium Heater (200 watts) has all the necessary features for safe and precise temperature maintenance of the water in your tank. The exclusive technology and the high quality of the components guarantee a long lasting product. Aquarium heater ideal for up to 100 gallon tanks. Temperature Controlled And Maintained By