Two orange-shoulder tangs managed to thrive in a tank with 5 sharks until they became lunch after 18 months of co-existence. Since their demise, I have had a ferocious outbreak of green hair algae on all the rocks, and of course cannot put any algae-eating fish in there anymore. I could use some input on what would cure the algae problem but would not be attractive to white tip, black tip and a nurse shark. thanks...