Hi Joyce,
I was using calcium powder with d3, but switched to TNT after I found out that you can cause damage by giving them too much calcium. I believe TNT is only sold at carolinapetsupply (but I could be wrong about that) and you can order it on the phone or online. I would not give your tort that box turtle dust that has all that protein in it.
Yes, you can feed them rose petals, as long as they haven't been treated with insecticides. I also give mine poppy petals, hibiscus flowers and dandelion flowers (and greens) as these are what grow in my yard.
