The substrate heating
The substrate heating washes nutrients to the plant roots
With a substrate heating you promote the growth of your aquatic plants enormously by creating a water circulation in the substrate, which washes nutrient-rich water directly to the roots. A substrate heating consists of a long heating cable which is laid in curved lines on the bottom panel of the aquarium. The water heats up directly at the cable and rises upwards. Between the cable loops the cooler water flows now, creating a water circulation in the bottom area which permanently washes nutrient-rich water to the plant roots.
A substrate heating is not meant to heat your aquarium water, it only serves as “micro circulation” in the bottom area. Therefore the wattage of the undergravel heating cable is significantly lower than that of heaters. You can read how to install a substrate heating here: Installation technical items .