The Hydor ETH In-Line External Heater is designed for vertical use in most aquarium applications involving water hose of the specified diameter. The ETH must be used in a vertical manner for correct operation. The most common application is for use with canister filters, however the ETH is easily adapted for use in almost any situation where heated aquarium water is required, such as with wet/dry sump pumps. The ETH is easily installed by cutting the tubing and connecting the two parts of the tube to each side of the ETH. For reduced maintenance, it is recommended that the ETH be installed within the filter’s output assembly. As most canister filters are not designed to bear weight, it is recommended that the ETH be properly supported by the use of the attached loop to avoid stress on the output assembly.

The ETH is completely safe and UL listed. There is no danger of damage if the ETH is left running dry for short periods as the ETH will switch itself off in that event. The ETH heats with high efficiency by means of an internal heat pump system that avoids temperature variations. For use in freshwater and marine aquariums. Fits most canister filters. This unit is intended for use with 1/2 inch (12mm) tubing.