i think my turtles are sick

Question
I came home last night and there was a translucent film across the top of the water. The other day i was talking to them(there are 2) and one bumped his head a little on a rock and this stuff came off from around his neck. It looked like peeling skin sorta. But i think that is what was on top of the water. I know their tank is clean. I was just wondering what this could be. Please help me if you can. Thank you!

Answer
Hi Lindsey. I have a few more conditions for you, but let me first say that if the turtles are exhibiting no symptoms aside from translucent patches of skin, they are probably not sick. If they are showing symptoms such as lethargy, wheezing, poor appetite, or excessive basking, they probably are sick and will need to see a good herp vet.
I think that both the skin shedding and the film on the top of the water come from 1 of 2 things; the water temperature or the amount being fed to the turtles. If they are under a year old, the turtles should be fed pellets once a day, and no more than would fit in their head if it were hollow excluding the neck. If they are over a year old, the same amount of pellets every other day. Fresh washed greens should be offered daily as well. Don't trust the little buggers begging. My turtles are notorious for begging right after they are fed. If I give them even a little too much food, a film forms on the water.
  If the turtles are under 1 year old, the water temp should be at 78 degrees, and certainly no higher than 80. If they are over a year, 74-76 is the consensus for water temp. If it is higher than these ranges, it can cause excess bacterial growth (the film), as well as excessive shedding, which your turtles seem to be showing.
  One additional question, how big is their habitat, and do you have a powerful filter for it? The standard most keepers go by for aquatic turtles is 10 gallons per inch of turtle shell length as a minimum. If the tank is too small for them that can also cause excess bio load, which could also account for film. A filter should be rated at 2-3 times the size of the aquarium. I have a 120 gallon aquarium for my 2 yearlings, with 2 XP3 cannister filters cleaning the water. Even with that amount of filtration, (good for up to 350 gallons), I still get that film occasionally.
 If the turtles are showing additional symptoms, or you have already done everything that I have stated might be helpful, please feel free to contact me again with questions. This is a website that is wonderful as a resource about the care of aquatic turtles.
www.redearslider.com
Thanks for the question! Nicole