Hobbies And Interests
Terrestrial and Aquatic
The most common species of turtles that are kept as pets are box tortoises, mud turtles, painted turtles and sliders. The most important thing to keep in mind about them is that they can be divided into two groups based on habitat considerations: box tortoises and mud turtles are terrestrial turtles; sliders and painted turtles are aquatic turtles. All of them are sociable and will be happier if you put more than one together in your habitat bin.
Containment and Temperature
For either group, there are two basic considerations. You will need a container to prevent them escaping or getting into trouble. And you will need to ensure that the turtles -- which are reptiles -- are kept relatively warm. The sides of the containers must be higher than the length of your longest turtle when she is fully extended. Turtles can climb. The sides must be smooth and vertical. Indoor bins need no heat; but outdoor bins will require you to put in a heat lamp or build a windowed, sunny-side enclosure for cold months and hiding places that hold some of that heat.
Terrestrial Needs
Terrestrial turtles need variety, beginning with soft and hard surfaces. Stone or concrete keeps their claws trimmed, and soft surfaces like dirt, leaves, and mulch give them places to relax as well as do their turtle business. Build in hiding places where they can seek shade or just chill, using vegetation or constructed space. They need a steady supply of fresh water and adequate space to roam around and sleep well away from where they defecate. The bigger the habitat the better, because these guys like to roam around. The more interesting your turtle bin is to look at, the more interesting it will probably be for the turtle.
Aquatic Needs
Aquatic species of turtles create an additional problem for you to solve with your homemade habitat. These guys are swimmers, and like fish, they need to swim in relatively clean water. This means you will have to figure out how to maintain the bin in the same ways you would an aquarium, with a system to flow water in and a system to aerate or filter the water. The other option -- not preferred -- is to change the water by hand every few days. Aquatic turtles need rocks or some other hardened feature that emerges from the water -- a basking area -- for them to climb up on and rest. This bask surface should be augmented with a heat lamp of some kind, at least during half of the day.