With no access to a land area, a female turtle will retain her eggs as long as possible and then drop them into the water or on her basking area. Retaining eggs for too long can injure a turtle - for example, an egg might rupture while still inside the female, leading to a massive infection. The size and depth of the land area is determined by the type of turtle - larger turtles will need a deeper area than smaller turtles to bury eggs. Also, some turtles are more terrestrial than others, and so benefit from a large land area. To make a land area, glue pieces of clear plastic into place with silicone aquarium sealant.
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.