[header] How to set up a turtle tank [title] Choose a large, sturdy glass tank. [step] Your turtle will need a glass fish tank that can provide roughly 10 to 15 gallons (38 to 57 l) (38 to 57 l) of water for every 1 inch (2.5 cm) of turtle. [substeps] If you do not have a mature turtle, base your measurements off the average size your turtle's species reaches upon maturity. 
Do not use a reptile tank designed for terrestrial (land-living) reptiles. The glass is too thin and can break due to the pressure of the water.