Fluval Submersible Glass Aquarium Heater, 50-watt

It is recommended to fill the aquarium with water that is close to the desired temperature you are trying to achieve. The aquarium heater must be positioned to allow for free circulation of water around the glass heater tube. Generally, the heater should be placed at the rear of the aquarium, preferably close to a source of water movement to ensure even and thorough distribution of warmed water. Be sure there are no rocks, decorations or gravel obstructions touching the heater to create uneven heat in the glass tube and weaken it.

1) Select the appropriate temperature by adjusting the Temperature Dial to the appropriate degree calibration.

2) Position the heater in the aquarium with the heater mounting bracket attached. Press suction cups firmly against glass to adhere to the aquarium wall. Wait 30 minutes before connecting to the electrical outlet. This allows the heater to adjust to the aquarium water temperature.

3) Note that it may take up to 12 hours for the heater to attain the water temperature you have selected. It is only after this time that the Easy-Set Temperature Dial should be adjusted to achieve a higher or lower temperature, as required.

4) The unit heats only when the pilot light is illuminated. When the pre-selected temperature is reached, the pilot light shuts off. It will light again only when the heater is required to maintain the temperature at the selected level.

5) The temperature should be verified with an accurate thermometer after the heater has reached the desired temperature, before any fish are added to the aquarium, and throughout the life of the aquarium.