Well, i wouldn't use any acanthurus to cycle a tank and I am talking about putting these into a reef aquarium, with coral and invertebrates and as I said, they are hard to acclimate, but I think that mine have been the hardiest tangs in an established reef aquarium. I would say that they are less susceptible to ich under these conditions and the most robust of the group. It is just that one so rarely sees them in this state because they don't make it past the initial shipping stress. So, I don't think that they are the best garden variety tang for a beginner but that they are very hardy once established