i just had a bad experience with a turtle not being taken care of from the in laws family, water changes once a month for a 20 gallon tank and the turtle was over 7 inches. when i would go over their it would have green water that was ridiculously smelly, and a filter that wasnt working, the turtle was to big for the tank and its floating basking dock and they didnt even have a basking lamp and had no idea it needed one,I took the turtle and put in a 125 tank. It took 6 months to nurse it back to health, and gave it away to someone who new his stuff.