ellman605 wrote:hmm, 50 litres? 24 C? man, why cant we all use a universal!!!
It's confusing for us because we live in the United States. We do things differently compare to many other countries. If I had to pick, I would blame the U.S. for trying to be so unique. When I first read this post, I also had to go online and look for a calculator LMAO. The Celcius thing I could do it in my head but that litre measurement is different. If the turtle is over 17 years old and she (if you know how to identify the gender Sally), she is definetely small for her size. Female RES can grow up to around 12inches I believe; give or take. Even for a male at 17years old age, the turtle would most likely grow to a potential size of 9 inches. By the looks of it, your turtle Sally did not have the suitable environment to grow into the potential size. I'm not going to say that the turtle was malnurished because since cam did an estimate of tank which is only 13Gallons, it's simply too small for the turtle at 5 inches to grow. I don't know anything about the dimensions of a 13G tank but in general, 10-15G are usually around 9.5 inches in width at average (some 10G/15G widths are 8.5inches while some are 10.5). This isn't even much room for the turtle to turn around in. Since you have been taken care of your turtle for 17years and also decided to search for answers to help your turtle, I can say that at least you're responsible enough to take action. You should ready the forums and find out the basic requirements for your turtle. But be warned, it will be expensive.
As for the concern about the neck, I can't really comment much on it. If you can take any pictures and post it, that would be good. My guess is that your turtle could possibly be stretching, looking and searching for something, or it could be a sign of discomfort maybe. I can't really tell since you didn't state much details. For the neck bulging, it's normal for turtles when they are out of the water. It is definitely noticeable when their necks are all stretched out. They are just breathing and it looks very similar to a frog croaking like cam has mention before. If you see any unusal marks, wounds, cuts, or exposed flesh, let us know so at least we can diagnose the problem. However, there is a chance you might need to take your turtle to a Vet.