300 WATT VISI-THERM SUBMERSIBLE HEATER, 1 PACK ...
25 Watt - 5 gallon tank, 50 Watt - 5-20 gallon tanks, 75 Watt - 5-25 gallon tanks, 100 Watt - 10-40 gallon tanks, 150 Watt - 20-50 gallon tanks, 200 Watt - 25-65 gallon tanks, 250 Watt - 50+ gallon tanks, 300 Watt - 55+ gallon tanks,. Now there is the Visi-Therm Deluxe - an advanced-design submersible aquarium heater that constitutes the next important step in aquarium heating technology. Visi Therm Submersible Heater 300W Marineland (Aquaria). For years, the name Visi-Therm has been the industry standard for excellence in aquarium heater performance and reliability. It is available in 25, 50, 75, 100, 150, 200, 250 & 300 Watt sizes. designed to exacting standards for extended submersion and operational safety.