The first task at hand is to find the appropriate tank for your turtle. Many people like to have two turtles so they can have a friend, which is perfectly fine as long as they are similar in size. I would recommend starting off with a 20 gallon tank for one turtle or a 30 gallon tank for two turtles. At first this may seem large, but turtles will nearly double in size every year for the first ten years. Also, some less common breeds of turtles can become so large one would need a kiddie pool sized aquarium for a full grown specimen like a snapping turtle. Since the most common types of pet turtles are sliders, painted turtles, and species of the like, I will focus on this sized turtle for the set up. Once the tank has been chosen, it must be cleaned thoroughly. The substrate must be chosen. Sand can be a good substrate for turtles because they like to dig and manipulate the ground, but its get very dirty quickly and is hard to clean. I would recommend common aquarium gravel in a darker color to hide and dirtiness. Clean the rocks thoroughly and lay them down across the bottom of the tank. Make sure you have enough to cover the bottom in around a inch or two of gravel. For a twenty gallon tank this will require around fifteen to twenty pounds of gravel.
Now you can add decorations. I would suggest large leaved plastic plants because the turtles will most likely eat or damage any live plants. Large rocks or pre-made caves can be placed for hiding spots and things for them to move around in the tank. Do not overfill the tank with decorations or else the turtles will have difficulty moving about the tank. Once decorations are buried in their desired locations, the tank can be filled with water.
When it comes to water, tap water will do just fine for turtles. I would make sure the tank is where you will be keeping it because once the water is added it will be impossible to move without emptying the tank. I wouldn’t fill the tank fully, but instead leave around three inches of water out for the nest step. Once the tank is filled, some sort of floating wood should be added to allow the turtles to leave the water and bask. These are commonly sold at pet stores and have convenient suction cups that allow them to move with the water level. Trust me, your turtles will love this and spent much of their time sitting on it basking in the light. For the lighting and cover of the tank, use the same as you would for a fish tank. Most stores sell covers with lights built into them that will work perfectly for providing light and making sure the turtles do not escape the tank. This will provide heat and light for the turtles to bask in. They also have a hole previously cut into them for a filter. When choosing a filter, bigger is better. The filters are typically rated by how many gallons the tank they are made for. Since you most likely are using a twenty gallon tank, it is best to chose a filter graded for a thirty gallon tank because turtles create much more waste and mess then fish, and you most likely will want to include fish in your set up for added activity in the tank. For a heater, make sure it is larger enough to keep the tank at the proper temperature which is around 70 -76 degrees Fahrenheit, the same as for fish
Since turtles eat fish, it can be fun to add small feeders to the tank for the turtles to chase abound and sometimes eat when the turtles become large enough. If your turtles are small, larger fish can be added for decoration and the turtles may pester them but wont cause them any harm. Once the turtles reach a few years old, don’t expect any fish you add to the tank to be used for anything but food. Turtles enjoy live food because they will love chasing them around the tank, but should be used mainly as a treat. Common turtle sticks should be the main diet as well as vegetables like lettuce for them to chew on. Once all of the mechanical aspects have been set up it is best to have the tank running with the filter and heater for a few days before adding the turtles and fish to make sure the water is clean and ready. Then add some goldfish to make sure the levels of any chemicals in the water are safe. Then the turtles can be added. Not much maintenance is required after set up except for feeding every couple of days with pellets and the occasional live feeder fish. The filter should be removed and washed on a weekly basis and changed on a monthly basis. The gravel can be removed and rinsed on a biannual basis. Water changes are not completely necessary, but to keep the tank healthy, partial water changes should be done every three months.
Now you can sit back and enjoy your new pets and their home. Turtles are very playful and can be taught to accept food from your hand with training. They also enjoy earthworms as a treat that is a good place to start when hand feeding. This set up should allow for a long, happy, and healthy life for your new friend.