I have a 29gal tank that's been set up over a year now. I have, or at least think I have, 2 nassariu snails, 4 or 5 hermit crabs, 5 astrea snails, 1 cleaner shrimp and 1 peppermint shrimp. I have seen both my shrimps go around on the sand eating bits of this that so I include them in my clean up...