Bringing Color to Life: GloFish fluorescent fish add an alluring array of brilliant colors to any aquarium. With a full range of vibrant aquarium kits, lighting and dcor, consumers can create an underwater fluorescent wonderland. Transform any aquarium into a GloFish environment at the click of a switch. The GloFish Submersible Heater is designed to keep your aquatic fish comfortable, with an electronic thermostat that automatically maintains a consistent water temperature of 78 degrees and prevents overheating, extending heater life. An indicator light lets you know when the water is heating (red light) and when it reaches the proper temperature (green light). Inside, silicon carbide crystals improve heat distribution and transfer. The strong glass tube is heat and shock resistant. This submersible heater is easy to use just attach to the inside of the aquarium wall using the suction cup (included) in an area with good water circulation. Use the GloFish Submersible Heater in aquariums up to 10 gallons. This heater is UL Listed. Born Brilliant. GloFish fluorescent fish are born with their dazzling colors! Not injected or dyed, they inherit their hues from their parents and add an alluring array of colors to any aquarium. With a full range of vibrant aquarium kits, lighting and dcor, consumers can create an underwater fluorescent wonderland. Transform any aquarium into a GloFish environment at the click of a switch.