[Rick,
All that hair algae does not sound "normal" in a new setup. (Maybe others have experienced it but in my 10 years of reef keeping I never have.) Let me start by asking what kind of water did you first use to fill your tank? RO is definitely a must.
200% water change sounds really scary to me. You will be starting all over again in cycling your tank if you do that much!
:uhoh:
Instead, do do a water change after trying to pull/scrape as much of the hair algae off as possible. (Suck that stuff out of your tank as well but still keep it a smaller amount of water 10-15%)
The brown "algae" is actually diatoms forming and is completely normal for a new tank, and what you should be seeing. Be patient and it will go away on it's own.
As for corals don't add them until your hair algae has receeded. Then you can start with mushrooms, zoanthids, and polyps. If your tank conditions are correct you will not be able to kill them.
:cool grin:
Hope this helps.]