Brown algae appearing after tank is going absolutley fine?

[Andreas' Reef]

My tank was going fine for a many months. So after I added the first round of corals to a mature tank, I got a ton of brown algae. I tested everything and it is all the same as when I had no algae. I have no clue what's happeneing. It's causing all the corals to close up. Does anyone have any suggestions as to what is happening?

 

[monkeyCmonkeyDo]

Coral looks.good to me. Id turn the light up a little. More flow. More filtration. I do see spots of diatom or brown algae but i dont see any outbreaks or real coverings of algae. Hths
D

 

[Andreas' Reef]

Coral looks.good to me. Id turn the light up a little. More flow. More filtration. I do see spots of diatom or brown algae but i dont see any outbreaks or real coverings of algae. Hths
D

Would putting in a bit more carbon help?