redearslider.com

In googling something unrelated, I stumbled across this comparison of turtle specific and some not turtle specific pellets.

I don't know that I'd trust it all blindly without further research, but it looks like a great starting point for looking at alternatives to what you are feeding now:

http://theturtleroom.com/blog/2012/04/2 ... pplements/

That page has been referenced a few times. I agree with you, a great starting point and interesting read.