Whether or not your turtles need heating depends on which species they are, how big they are and whether they are kept indoors or outdoors.
Indoors
If you are keeping hatchlings in the southern parts of Australia or if you are keeping tropical species indoors, you'll need heating.
Heating indoor tanks is normally done two ways. The first is an aquarium heater. Depending on the species, this is normally set to keep the water at about 22ºC.
The second source of heating is from a basking lamp. For a tank, this can be something as simple as a clamp on desk lamp with a flexible neck. A standard globe generally provides sufficient heat for basking. Position it above your land/dock area. Set it up close enough to provide warmth, but not close enough for the turtles to reach up and burn themselves.
The basking lamp can be connected to a timer, so that the turtles experience a day and night cycle. All lighting should be turned off at night.
Outdoors
Turtles kept outdoors do not need additional heating, especially if they are suited to the climate they are housed in. Keeping tropical species outdoors in cold areas is not advisable.
Most turtle owners keep their turtles in heated tanks for their first two or three winters. Once the turtles are 8-10cm, they are big enough to survive outdoors all year round. The best time to introduce turtles to an outdoor pond is in Spring. Once the pond temperature has risen to the same temperature as the indoor tank, the turtles can be transferred to the outdoor enclosure. They can then gradually warm up over the Summer months, before slowly cooling down as they head into the following Winter.
