Ista External Inline Aquarium Water Heater Tropical Marine Fish External Heater

The Ista External Heaters are the ideal solution to heat your tropical aquarium without having to have an unsightly heater in on display in the aquarium.

The External Heater fit’s inline with your return pipe from an external filter and heats the water as it passes through the thermal spraying glass structure of the unit. The thermal spraying glass also speeds up the heating process making the heaters extremely efficient at heating your aquarium.

Two temperature sensors continuously monitor and display the temperature on the 2-line digital display and adjust the heat produced accordingly. The 2-line display shows both the set temperature and the real-time water temperature.

All Ista External Heaters are equipped with an auto power off system which shut the heater off if: the temperature rises 3°C above the set temperature, the temperature difference is 5°C or more between the two sensors or the temperature detected is over 36°C.


The Ista External Heaters are available in three models. Please select the required size from the dropdown menu.