It depends on how big the turtle is, if there is sufficient space for the turtle to move around then it should be fine. You might want to invest in a 20 gal flat aquarium, these turtle like shallow water, just low enough to bury in the sand and still be able to stick there nose out of the water. Another option is a small wading pool, these make great habitats, you can even build a filter out of a small bucket, foam pad, and a submersible pump, just cut a small hole on the side of the bucket just big enough to allow the intake of the pump to fit, then cut 1'' slits on the side of the bucket at the top rim, make four. These should be about a quarter to half inch below the water line, place some heavy rocks in the bucket and place the foam over the rocks, pre-cut the foam to it fits the diameter of the bucket.The water should cascade down into the bucket, just experiment until you get it is right. This filter will create a current and keep the water crystal clear.