PULACO Your Creative Aquarium Mate ! PULACO provides you with quality Aquarium services. We are committed to being the best Aquariums store you can trust. PULACO Aquarium Heater 50 Watt How to use the external controller: Plug in, the controller LED lights on, press the button and switch it continuously until the LED display shows your expecting temperature (From 68~93℉ ), and wait 3 seconds for system confirmation, then heater will start heating up to your preset temperature.Red lights means the heater is on heating mode, when heater heating up to the preset temperature, blue lights on, and heater will stop heating (Restart heating when temperature less than preset temperature) Operation for example: Plug in and LED display shows preset temperature 68℉, you want adjust it to 78℉, then press the button 10 times continuously, LED display will shows 78℉, and wait 3 seconds flashing, then setting fishined, heater will start heating from 68℉ to 78℉. Maintenance: This heater is free maintenance item, for the good of heater function and service life, we suggest: Check the heater working status regularly, if any strange signs,please plug off immediately.Clean the heater suction cups regularly (3 months)with 140℉ warm water and soak it for a while.If you found any soil or moss things covered on the heater, please plug off the heater and clean it with fresh water after a few minutes later, especially the heating part stains. Do not use any other liquid to clean the heater, it may damage the heater Cautions: Please install and use this heater under rated voltage conditions(110V-120V/60Hz).This heater is designed for small fresh/sea water tanks, please do not use it in chemical water or any other heating purpose, it may damage the heater.Children should be use this heater under adult's guidance.IPX8 design, non-detachable, do not disassemble it, otherwise it will damage the heater.To ensure the heater normal functions and safety concerns, heater should be fully subermerged.Fish tank temperature is very easy to affected by the room temperature, therefore it makes the water temperature inaccurate, normally ± 3℉ differency.To help the heater works more efficiently, please use the heater in a circulating water tank, still water will make the heater area water temperature higher than other side. External Controller External LED temperature display and Touch button, cyclic adjust temperature , easy to use and Safety. Quartz glass heater The heating device is made of heat-resistant quartz glass Specification Power : 50Watt Voltage: 110-120V/60HZ Cable Length: 5.0 ft