Hey I'm sorry I can't help with your red-leg question (I'm having some health issues with my own currently) but I wanted to mention that you should probably change their substrate to something that they can't swallow so easily. My herpetology instructor told me that frogs should always have rocks that are bigger than their mouths so they can't swallow them...they could end up swallowing that sand when they eat their food items and over time it can accumulate & block up their digestive system Their is also frog moss, which is awesome, and sphagum moss--but the sphagum can also cause issues if not maintained properly.