Hi
Jumping in with far less reef keeping experience than others but I can honestly say GHA was one of the easiest problems to fix in my system, I bought a bunch of blue hermits, upped my water changes and it took care of itself, you could also try carbon dosing. I have all kinds of undesirable stuff in my Fuge but my DT is clean as a whistle, I only keep LPS and softies in my tank but I don't even run a skimmer anymore, I have a large fuge and a GFO/Carbon reactor with 15% WC weekly and everything is good. not saying get rid of your skimmer, but your going to have all kinds of random problems in a new system and Hair algae is really one of the easier ones to fix.