Turtles are sold at all sizes, ages, and species. It is important to know that each needs a different type of maintenance and how to spot the differences between types of turtles. In order to provide the best turtle care, specialized care is the best way to go. Some turtles do not need to eat every day and some do not like to be in water at all. Those turtles are land turtles and live best in outdoor habitats. It is essential to provide them with a pool to swim in for the few times they would like to be in water to cool off, since they are cold-blooded creatures. Some turtles like to live in water all the time, with special habitats and dwellings at the bottom of the tank. Other considerations are with what to fill the tank. A salt water turtle and a fresh water turtle can absolutely not live in the same tank. Some turtles prefer  grassy bottoms of the tank, while others need sand, like softer-shelled sand-dwelling turtles. This proves true for more aggressive turtles and friendlier turtles. Those should be separated.