How is my lizard tearing hi..

I have a young gold tegu. He is very healthy and energetic, but not completely used to being handled (working on it.) I keep him in a 55 gallon tank and he's got his Ground Walnut Shells bedding and his hiding log and water bowl. Somehow, his feet are really badly cut and torn up, and I don't know how he's doing it. It's not because of the log, because it's the exact same one they had him with at the pet store I work at and he did fine. I'm guessing it's because the skin on his toes is not shedding properly. He is always soaking in his water bowl, so I've started filling my bathtub up just a little for him to lay in for a bit. He seems to enjoy it, and it looks like it's helping, but not much. He's a beautiful lizard and it makes me sad knowing he's in this kinda pain. If you have any other ideas as to what may be causing this, please let me know. I also have some pics, if it will help.

For some lizards, walnut shells are too rough (just try walking on them yourself 24/7). Even though walnut shells look attractive as a substrate - seeing a necropsy of a bearded dragon impacted from those shells was enough for me to discourage folks from using them.

We recommend using seeds as substrate. You heard right - seeds, like the birds eat (millet or flax work well) - smooth and safely edible!!! Just don't use sunflower seeds - the shells can cause problems if eaten. We buy 50lb sacks at the co-op for a reasonable price (less than the shells).