I've had them years ago, but they didn't last long--- it was a newbie mistake. Some got caught up in low positioned PH's, the others just popped up dead on the sandbed. They wont eat anything from the sandbed, they are filter feeders. If you tank is ready for inverts and you are supplementing for filter feeders then you could be ok. You wont see them alot--they dive (literally) into the sandbed within seconds and throw up their "feeders" every once and awhile. See what others say, I have limited experience on them.