A quality aquarium water heater is necessary if you intend to maintain a successful tropical freshwater, marine fish or reef system. Temperature fluctuations often go unnoticed by aquarists and can cause stress to fish and corals. Most fish tank heaters include a built-in thermostat to select the optimal temperature for your aquarium, however, the use of a thermometer to monitor the temperature is highly recommended. You might consider a temperature controller for keeping a stable environment in your aquarium since they offer more precise readings and a more advanced feature set. A minimum of 3-5 watts per gallon is recommended to keep aquarium temperatures at an optimal level. Aquarists with larger tanks should consider using more than one heater. In the unlikely event that your heater goes, have multiple heaters in place safeguards your tank from crashing. For more information about aquarium heaters and to read product reviews, please visit our website: marinedepot/Heaters_for_Saltwater_Aquariums-FIHT-ct.html... Aquarium heater aquarium heaters submersible aquarium heater fish aquarium heater heater for aquarium Aquarium water heater small aquarium heater fish tank heater Aquarium Heaters ZooMed Mag Clips The Via Aqua AquaTop Submersible Aquarium Heaters Most aquarium fish come from warm waters and need to be above room temperature Aquarium heaters are inexpensive and keep temperatures stable … Nov 18 2011nbsp018332A quality aquarium water heater is necessary Aquarium Heater Fish Tank Heaters - At AquaCave we offer some of the best selection