OK, OK, OK...enough of bad mouthing sand starfish. Ctimpson, they are just fine to add to a tank that has been running 6 months or longer. They run around the sand, eating stuff, but they move SLOW SOOOO SLOW, it is almost painful to watch them move around in the sandbed they are so slow. I have three in my 125. My live sand seems to generate life all the time. I don't think anyone here has them nor has had them due to fear or just jumping on the bandwagon. If you want one, get one. Add one every three months til you have three. They do just fine.
-Doc