I found a couple of spots in the spa where the plaster was flaking. When i prodded it with fingers, the flake came off to reveal algae hiding behind it. I scrubbed the spot with a brush (pool /spa was in shock) and more plaster crumbled. The damaged area is now about 2-3 square inches. The pool is not leaking and I don't think the damage is enough to have reached the shell.
Can I use EZ patch 1 FS to repair this area? Or is this a sign to re plaster? Any help would be appreciated.