Undergravel heating - not for heating the water!

Despite its name, the undergravel heating ( JBL PROTEMP b III ) is NOT intended to heat the water like a heater thermostat (e.g. JBL PROTEMP S 100 ) does, it is only for water circulation within the substrate.

The undergravel heating consists of a cable that is laid in snake form on the bottom glass plate of the aquarium and fixed with suction holders. It is then covered with substrate and/or gravel or medium fine sand (do not use with very fine sand!). The heating cable heats up and the warm water rises to the top. Colder water flows in and thus a circulation of the water INSIDE the substrate is achieved. This leads to an ideal nutrient flushing of the plant roots and ensures strong root formation and thus healthy plant growth.