If you have a lot of hair algae. You might wanna pull the rocks and scrub them down in some of the old salt water when you do a water change. You might also wanna invest in a "sea hair" my understanding is they mow through hair algae like its nothing. However, once it's cleaned your tank if there's no algae they will slowly starve to death. You could return them to the LFS
or pass them on to a friend who is also having hair algae problems.
You could also invest in a phosban reactor with some good GFO
. I use Dr Gs, and it seems to do fairly well. I had a lot of hair algae and I'm down to about two spots that are about the size of two golf balls.
My issue is algae "dust" on my glass and my substrate. Still trying to figure that one out.