Soft Shell on a RES

Question
Hi, I got a red eared slider on may 16, 2009, the day he was born. Well, I am emailing today on august 4 2009. His shell is more like rubber, especially in the back. My dad says its probably because he is too young and he says by january it should be a bit firmer. Its not a calcium problem I'm sure, because I put about a pinch of calcium dust (It says on the ingrediants its 99% calcium) in his cage each day, and feed him mealworms, along with freeze dried shrimp and krill, along with other things. I've been doing research for a while, and I'm just wondering, is it the lighting, maybe? When he was in a 10 gallon tank I had him on a 50 bulb im pretty sure, and when I decided to put him in a larger tank of 20 gallons, we went ahead and got him a 75 bulb. Is it the light, or is it age, or is it just somehow he hant been absorbing calcium? I dont feed him fruits or spinach, so Im not giving him anything that could keep him from absorbing calcium. Not in much of a hurry, but I would still like a quick answer! Thanks!

Answer
Hello Crissy,

It sounds like you are giving him ample calcium supplementation.  Do you feed nice dark green leafy veggies & greens too, as well as specially formulated turtle food such as pellets along with the feeders?  The foods you are feeding should not be binding his calcium, especially if you are not feeding spinach or bananas which are particularly high in phosphorus.  
No, his age has nothing to do with shell hardness.  He should not have soft shell at any age.  So you still have time to correct this before his health declines & his shell begins to pyramid & deform on him.  
The lighting is extremely important.  Are you using a UVB light?  If not, that is the primary reason that he is not absorbing his calcium properly.  
For a Red Eared Slider, a Reptisun 10 flourescent tube bulb would be great to use with him, in combination with a nice bright white basking light such as a regular household bulb or a halogen bulb.  He is in a 20 gallon, is that correct?  The 75 watt should be ample wattage for heating.  What are his temperatures?  What type of thermometer do you use to measure his temperatures?  A stick on type, a digital probe or a temp gun?

Tracie