If you have
green hair algea, it is best to scrub the rocks that have it to free them of the long hairy algea. Check the nitites to see if you have them, if so, all inverts will probably die if you add them. I would change the sand to a reef sand, Fiji Pink or Oceans Direct both from Caribi Sea.
A phosphate reactor will help long term, and alot of carbon and NO LIGHT will also be a plus.
I bought a 125 reef system that had a ton of
hair algea. We wrapped the tank for 2-3 weeks in a blanket, did 25 % water changes to it once a week and most of the hair algea died off. We (Stacie) then removed the rocks and scrubbed them with a course brush like you would use to clean the tires. It was new of course. Mexican turbo snails were added 10 or so and the carbon was changed every week or two. 1+ pounds at a time.
It did fine after that. The same rock is in my 210 that we upgraded to.
The brown stuff is most likely diatoms, it is common to new setups and higher Total disolved solids (TDS) in the water. Some salt mixes cause issues as well. When I switched from Oceanic to Kent, improvements were notice after that water change.
Do you have any pics of the green algea?
Use only RO or RO/DI water when adding water to the tank.
Low flow areas are always going to be your problem spots.
A big skimmer is also helpful in water quality.
Many are helpful on this board, so please ask questions. Someone will help.
Don't be intimidated by the new system, enjoy it. We have all made mistakes, some cost more than others, but it is for enjoyment.
Please post if you have further questions and
CONGRATS on the new Tank.
Eddie