In native plant biotopes soft, permanent horizontal and vertical substrate water movement will provide excellent nutrient distribution and a well-balanced redox potential. In trying to copy this natural substrate environment found in tropical waters in aquariums, and thereby assist healthy plant growth, substrate heating systems (e.g. Duplaflex floor heating cables) have been found to be a well-proven and established method. It distributes nutrients to the roots through convection currents for optimum plant growth. You will still need a heater to heat the aquarium, this heats only the substrate. Now it is affordable for aquariums up to 32 gallons. The Duplathermik-Set includes a safety transformer with a secondary low voltage of 24 V. The Duplamat 20 is splash water protected, and also comes with integrated thermo protection. The attached silicon-coated floor heating cables operate at 24 V. The power input is 20 VA. Plugs in to regular household plug-in (115v). Dupla Thermik Set (Heat Cable) DUPLA Thermik Set Omega Floor convector for plant root activation.  10 feet of Silicon 20watt heating cable suitable for tanks up to 32 gallons Low Voltage (24v) : transformer included. Fitted with US plug Permanent 20W source of heat Activates root development Supports biological circulation Suitable for all aquariums up to 32 gallons An affordable entry product for substrate heating