Aqueon Glass Adjustable Aquarium Heater, 200-watt; Keep your fish happy and healthy in the ideal water temperature with the adjustable and accurate Aqueon Glass Aquarium Heater. Whether your fish tank is freshwater or saltwater, you can easily ensure the aquatic climate is the right one for your finned friends. With a convenient and precise temperature dial, you can adjust the temperature with a flick of your wrist. Meanwhile, you can rest easy knowing that the shatter-proof construction will keep your fish safe and sound. With a wide range of available wattages, finding the right heater for your aquarium is a snap, and it comes with an automatic shut-off feature to help keep your fish swimming safely along.