Red Eared Slider Turtel

Question
I just got this turtle and i dont know what the tempetur is suposed to be in his tank i keep it at 70 degrees is this right?i also don't know genderand I also don't know how old it is can you help me?

Answer
Temps- water temps should be 75-80 and basking site temps should be around 90.

Gender- young turtles are almost impossible to sex. As they get older, it is easier to see that male's tails will be long and skinny and the female's short and wide. The male's belly will be incurved and the female's flat or slightly bulging.

Age- we can guess the age by counting rings on the belly scales, but it is only a guess. You can use size charts, but they don't help a lot either.

Other: I'm betting that you need some other help as well- for example, I'd bet the tank is too small. Turtles need about 10 gallons of water per inch of turtle. They also need a good diet, filtration, and lighting.

For some good articles on each of these issues, try:
http://www.austinsturtlepage.com and/or
http://www.redearslider.com