More intricate arrangements are also possible. This set-up lets the turtles pass underneath, allowing them to move from one end of the tank to the other without going up onto the land area. For example, in this enclosure , the edge of a brick supports the horizontal piece of plastic, whereas the thickness of the plastic is sufficient in this setup . A fully submersible water heater helps keep the water at a reasonable temperature year-round, as many water turtles prefer water temperatures that are above ambient room temperature. However, the temperature of the water will depend on the type of turtle that you keep, and therefore you should investigate the natural environment of your turtle, if you are not sure of its requirements.
Most underwater heaters attach to the side of an aquarium with suction cups.
If your turtle is very active, it may become necessary to wall off the heater to some degree to prevent the turtle from breaking it. Also, buy an aquarium thermometer. Many heaters are not accurate and require monitoring to assure that the desired temperature is maintained. A filter of some type can also be quite useful. I prefer the fully submersible type that do not require an air pump, but are self-contained units, sucking water in through the bottom, passing it through a sponge filter, and expelling it out the top.