I have 3 tangs and they only nibble at red turf algaes(as there are many types) I use 7 sea urchins instead. My tank is a 180g. Coralline algea grows rapidly in my system.
Oh, I thought it was the fact I haven't changed my RO filters in 2 years... Dumb meter still said 000 on there, just took forever to make water. Now that I've changed the filters, it says 009 going in & 012 coming out!