Our pet fish originate from all over the globe and water temperatures vary immensely in their native environments. To be able to keep fish in an environment which is conducive with their natural habitat, we mostly will need to increase water temperature above normal room temperature.The Aqua One Glass Heater range provides a great heating solution for each aquarium set up.Suitable for: Cold water, Tropical & MarineQuality and economical heatersCompletely submersible with double insulationsHeater thermostat with easy to use temperature settingsLarge temperature range 20C – 34CAutomatic shut ‘off’ and ‘on’ light