Name: Acanthurus leucosternon
Origin: Indo-Pacific Oceans
May be difficult to acclimate: offer hiding places. Regarding feeding, my specimen eats almost only dried algae, sometimes a little of flakes. It also works fine in keeping rocks clean from encrusted algae. Mine is in a tank with other 6 small fishes (Amphiprion ocellaris, Crysiptera paraesema and Chromis) and I never saw him aggressive.
Will accept frozen brine shrimp once used to it. Though a friend's has done well in 120 liters, it's a tight fit and seems a bit cruel - the Powder needs room to roam.
Will rule the tank if there are any juvenile coloured fish, like the emperor angel. If there are other like-sized fish in the tank, make sure there are enough hiding places for all of them to avoid disputes, otherwise the scalpels will come out and result in fish looking like they have marine velvet.
One important factor to have healthy powder blue tangs and other rather sensitive surgeons is to use a Good UV-filter. Also provide them with dryed Nori algae (big sheets used for sushi) at all times. Healthy powder blue tangs are really fat over the back and have a round "beer belly".
I have had a PB for almost 8 months now in an established reef tank. I chose him from the store due to behavior and eating habits. He ate flake food and was not shy at all in the community evironment at the store. Furthermore, he was at the store for almost 2 weeks and his color was still good. The PB color really is indicative of how stressed/healthy they are. It is very important to use either Ozone or UV to control inevitable parasitic outbreaks. I've had only one outbreak that was a result of my one of my pumps not working to capacity. By having a Orp meter I detected that something was wrong and fixed the problem. However, the damage was done and the PB had Ich for almost 2 months. I kept him well fed on multiple foods dosed with Garlic elixir and vitamins and stayed away from any type of medication. Now he's back on his feet! Further mention, I keep the PB in a 340 L reef in which I added him last. I have a Purple tang (slightly smaller), a Bi-Color Angel, Coral Beauty, Coris Gaimardi, 6 Chromis, and 2 Anthias all co-habitating wonderfully.
I recently returned my powder blue to the aquarium store. I have all tangs, and this was just too much for him to handle. He fought with my blue hippo tang and absolutely hated my sailfin tang. At first he was fine with all the tangs, but after six months he became a little monster...but that is party my fault. Should have read up more on this species as I have done in the past for my other fish...guess it was just an impulse buy...very bad thing to do. I think in a reef tank with only a few other small fish, he would have done beautifully! I fed him dried seaweed, Formula 1, 2, Angel formula, Mysis/brine shrimp. Coloration was excellent and I also used a UV filter on my tank...very good to have! I also used a little bit of selcon each week on their food to boost immune system.