turtles

Question
my daughter has large outside pond with a variety of turtles which she has maintained for several years no problem till recently she wanting to know why their bottom of their shells are turning red. she lives on the beach water quality dont know but is this normal?

Answer
Hi Jackie,
Sorry, but I have very little experience with turtles, my knowledge is mainly concentrated on aquariums dealing with fish and planted aquariums.  I do not want to give you the wrong advice.  Have you tried the experts that are focus on turtles?  Here is 2 links to them.
http://www.allexperts.com/el/Reptiles/
http://www.allexperts.com/el/Turtles/
-Matt-