I've been having a bit of a problem with my snails. My snails' shells haven't been looking too great as of late, even though they have boiled cuttlebone in their tanks to eat directly from if they need to. I considered crushed seashells, but that would raise my kH as well as my pH, which is already high at 7.6. I don't want the pH to be raised any further, and RougeAgent suggested using calcium carbonate. I also own two Fat Tailed Geckos and I always coat their food in this - Credit: http://www.reptile-food-direct.co.uk/acatalog/zoo_med_repti_calcium_D3.html (Click for more information) This seems to be ONLY calcium carbonate with vitamin D3 added. Can I use this for the snails too?