I have a Diamond goby happily living in my 28g nano, but when the time comes he(she?) will be moved to my soon-to-be 65g. He currently is enjoying the oolytic aragonite sugar-sized sand, as he is an avid sand sifter! For the new tank I have the Caribe Sea, Sea Flor Reef Grade sand. It is a nice uniform granular, but much coarser than the other. My question, will this be too much of a change for Mr Goby (Tito, to friends)? My guys at the LFS said he would be fine, as that's what they use and they are happily sand-sifting there (once again saving me money!). A very, very entertaining fish! Here he is hanging with our new torch!