You may be able to put the mud on your crushed coral. But what part of the Atlantic. If you are up north I would not do it....Also those hermits will get large if you have shells in the tank for them to switch into. Otherwise they will eventually will weed themselves out fighting for the "biggest shell". I used to keep them as a boy on Cape Cod...but they never lived long...I would be careful about mixing things that are not from a reef environment...Hope this helps.....