I have had my red eared slider for about a year or so and for the past 3 weeks he has looked depressed. i dont know if it is depression or if it has to do something with his health. my turtle (shelly) has not been eating much and when i go check on him he is on the basking dock sleeping and he looks pale. when i give him pellets he snaps at them slowley and when he gets them in his mouth he finds it hard to bite on, so i give him soft food like shrimp and krill but when he tries to eat it he bites it but then spits it out and usually he ends up eating only bits of the food. and i have also noticed that he has wrinkles under his eyes and i wonder if it has anything to do with the water quality.

can anyone help me resolve this problem.