Most ppl freak out when they get into the diatom/algae stage of their tanks but its a normal thing. You'll get brown then green and then probably red/pink near the end of it all, and the pink will stay around for a long time and probably turn into coralline. I have astrea snails that really tear up the algae they keep my live rock clean and im planning to get nassarius snails that stay on the sandbed and clean it. If youre really concerned id invest in whats called a critter pack. Its hermit crabs/snails/shrimp etc that love to eat that algae.
As far as ro
its a really good investment and keeps your water clean. I dont know how clean your local water is but chances are its not that good. Funny how we keep our tanks using good water but we drink tap water
. Boiling it doesnt really have a great effect, it might kill microbacteria but it leaves in trace elements like copper and other phosphates. Id seriously look into getting a skimmer if you dont already have one. Check your water levels a lot for calcium/nitrates/nitrites(if your cycle isnt over)/ph
/ and alkalinity and keep on top of salinity. Other than that you cant really do much, i know it looks ugly with brown algae but its how the tank matures. Just gotta keep with the golden rule of salt tanks...PATIENCE, and also this forum is great for advice, many knowledgable ppl here.