Posted: Sun Apr 12, 2015 2:18 pm Re: i have a question!!!
When was the last time you changed your UVB lights? A lot of people tend to change them after about 6 months, as they stop giving out UVB and therefore Vitamin D3 (which converts calcium into a usable form, which hardens the shell). Also important here is your light placement. It seems that your heat/UVA bulb is centered above your basking spot, but the UVB one is above the water. Your turtles can't adequately absorb UVB rays in the water.
Giving calcium does no good without any sources of Vitamin D3--whether dietary or light-based. A soft shell is usually the result of D3 deprivation, and a MBD symptom! All that being said about the lights, I also looked at the Wardley's pellet ingredients, and they don't contain Vitamin D3 either. All of these things are possible reasons for your turtle's soft shell problem.