With the leather (aka devil hand, finger leather) they are easy to keep and are hardy. They tend to do best in medium flow as they shed. The flow will wash away their skin, this can also easily be accomplished with a blast from a turkey baster. If you don't have one get one, turkey baster that is cause they are very handy in a reef tank. From blasting corals or algae away to target feeding. If you notice the leather not opening then give it a blasting to remove the skin and it will usually open shortly after.