Thank you for waiting. Unfortunately, whoever gave you information on turtle care steered you very wrong. Turtles are much more difficult to care for than we imagine. So even though, you've tried to keep your turtle healthy, he now has more than one serious health problem. I'll give you some measures to take.
At room temperature, your tank is too chilly, and that can lead to the shell problems you're seeing. The basking area should be kept at 88-92 degrees. The rest of the tank should be around 80*F. You can adjust the temperature by raising or lowering the light fixture. You'll also need a submersible aquarium heater that will keep the water in the low 70*'s. I'd warm up the tank to the proper temperatures right away. Warmer temperatures can give the immune system a boost.
Sunlight coming through windows does no good because the window glass is manufactured to filter out UVB light. It's extremely important that you buy an additional light that produces UVB rays. A Reptisun 10.0 is a good brand that does. If you choose another brand be absolutely certain it provides UVB rays. Don't take the word of pet store personnel, but read it for yourself. Full-spectrum, DayGlo, daylight, UV, and UVA are NOT the same thing. I'm putting a lot of emphasis on this because it's crucial to a reptile’s health. Without this light, Metabolic Bone Disease (MBD) will develop because they won't be able to produce vitamin D. Vitamin supplements are not a good replacement for the proper lighting. MBD causes a very slow and painful death. Your turtle's front leg problems are very likely due to MBD. UVB bulbs must be replaced every six months as they lose their effectiveness after that, even though they may still look fine. The other step you need to take to reduce MBD is to provide calcium. Put a cuttlebone in the tank - just float it on the water. cuttlebones are sold in the bird departments of pet stores.
Without proper conditions and some veterinary help, your turtle is likely to die in the next few months. These links will take you to directories of vets who treat turtles:http://www.austinsturtlepage.com/Info/state_resources.htmhttp://www.nytts.org/nytts/helpnet.htm
In summary, I recommend getting both types of light and adjusting the temperatures, provide a cuttlebone, and schedule a vet appointment. If this is more than you are able to take on, let me know and I'll try to find a turtle rescue which will take the turtle. I'm also sending along a care sheet I've written for painted turtles (some of the information above comes from it). You can use it as a checklist to make sure everything is right. If you have more questions, of you want me to find a rescue, just let me know in a REPLY. I hope your turtle will be able to recover.
AnnaMy goal is to provide you with excellent service – if you feel you have gotten anything less, please reply back, I am happy to address follow-up questions. Please remember to rate my service only after you have all the information you need. Thank you!PAINTED TURTLE CARE SHEET
Well-cared for turtles can live 30 years or more.The Tank
It's recommended that a baby have at least a 15 gallon tank. By the time the turtle is 3-4 years old, it will need a 60 gallon tank, so it's best to get the biggest you can in the beginning. You can also use a large RubberMaid tote. That's not as pretty as a tank, but costs a lot less. Set up the tank so there's a land area and a water area. Put the basking light at one end so the whole tank doesn’t get too hot. You want the water to be about twice as deep as the turtle is long. If the turtle is two inches long, you'll want four inches of water.Temperatures and Basking Area
Turtles need certain types of lighting and need to be warm. Air and water that are not warm enough can lead to fungal and respiratory infections and unhealthy shells. Turtles must have a basking area where they can get out of the water, dry off, and bask in very warm light. The ambient air temperature in the tank should be around 80*F, with the basking area warmer still. Over the basking area there should be some sort of lamp that will take a 40-60 watt incandescent bulb (or you can buy a ceramic light fixture made just for reptiles). If you live in an area that has farm stores, you can buy a metal light fixture made to keep baby chicks warm for just a few dollars. Don't buy the accompanying bulb, however. You need an ordinary incandescent bulb in the basking light. Hardware stores sell similar fixtures as work lights. The basking area should be kept at 88-92*F. Use a digital probe thermometer to be sure. You can adjust the temperature by raising or lowering the light fixture.The lights that come with the covers on aquariums are not suitable for turtles. You'll also need a submersible aquarium heater that will keep the water in the low 70’s.UVB Light
It's extremely important that you buy an additional light that produces UVB rays. A Reptisun 10.0 is a good brand that does. If you choose another brand be absolutely certain it provides UVB rays. Don't take the word of pet store personnel, but read it for yourself. Full-spectrum, DayGlo, SunGlo, UV, or UVA are not the same thing. I'm putting a lot of emphasis on this because it's crucial to your turtle's health. Without this light, Metabolic Bone Disease (MBD) will develop because your turtle won't be able to produce vitamin D. Vitamin supplements are not a good replacement for the proper lighting. MBD causes a very slow and painful death.UVB bulbs must be replaced every six months as they lose their effectiveness after that, even though they may still look fine. Light that comes through a window isn't sufficient because the glass filters out most of the rays turtles need to stay healthy. To prevent MBD, turtles also need calcium. The easiest way to provide it is to place a cuttlebone in the tank. Cuttlebones are sold in bird departments of pet stores.Filtration
Turtles are very sensitive to water quality. Even if you change the water every day, it can still contain harmful chemicals. A good filtration system is essential. Water changes are also needed even with a filter. If the tank is too small, no filter can keep up with the amount of waste that turtles produce. Feeding
Feeding is an area where pet stores often give out bad information. Commercial food and animal products (meat, earthworms, canned cat food) should make up about 3/4 of the diet. The remaining 1/4 should be plant foods (dark lettuce like romaine, bits of strawberry or melon, etc.) Hatchlings should be fed every day. Older turtles should be fed 3 times per week. Overfeeding can lead to gout and kidney failure.