If they have any trochus snails I would grab some of those. My 29g biocube is fairly new and going through the uglies. I have about 20 cerith snails 5 nerite 5 astreas and 2 trochus snails that I just barely added and they seem to be very effective. Also they can eat hair algae which the other snails will not. but maybe that's not a big deal since you are doing hermits. I think they chop down the hair algae. I'm trying to go no hermits currently.