Lol, no intention of thread jacking.....I live on the Gulf coast and state law allows for a minimal number of sanddollars to be collected. It's a pretty strict law, and if your thinking of collecting any, I advise knowing what your state allows. Anyways, one day whilst snorkeling, I happened upon thousands either breeding or migrating and couldn't pass up the chance.
So I grabbed a few, acclimated just as you would an urchin, and voila, clean sand bed. There is some concern about them being too efficient in waste removal, so I currently only house nickle size specimens with exception to one larger one, about the size of a silver dollar. There's certainly a good chance of me returning them to the gulf once they get too big for my system.