I've had bad luck with them in my 72G. Its not too easy to keep them with other fish, cause these guys like(Basically) Dirty water. Being a filter feeder, its hard to keep them from starving to death when you keep the water PERFECT. I have 3 in my Bowfront and I was down to 2 in 3 Weeks than the Last one died about 6 weeks later. I dont know how it even lived that long. The only reason I knew he was dead was that My Lobster in there Dug him up and was dining on him. Thats another thing about them as well, Even if you go for them, theres not much to look at after a while cause all the do is Bury themselves.