Keeping tropical fish in the BiOrb is easy, simply convert to warm water with the BiOrb Heater Pack. A wider selection of fish can be kept by converting the aquarium to tropical. To do this the water needs to be warmed by an aquarium heater.  Key Features Easy to Mount to the BiOrb A Heater Stand is also supplied that enables the heater to be fitted securely onto the curved surface of the BiOrb. There is a lead from the Heater which needs to be plugged into mains power and there is a section in all of the BiOrb lights which allows the lead to pass out of the BiOrb neatly. Set and Monitor Water Temperature The Heater Pack contains a 50watt standard aquarium heater capable of heating the water in any BiOrb up to 60 litres. It is also important to monitor the temperature of the aquarium with a thermometer. An accurate glass thermometer is supplied in the Heater Pack. Included in the box: 50 watt Mains Aquarium Heater Clear Acrylic Heater Stand Glass Thermometer Sample of Tropical Fish Food is also included