I’ve been noticing this brown algea growing on my rock and the walls of my tank. This hasn’t happened before it and it has completely ruined my tank. My corals have closed up and my clownfish is being weird. I’ve done frequent water changes, used a toothbrush to scrape as much of it as I can off, but nothing seems to work. Can anyone think of a way to fix this? The pictures aren’t amazing but that’s the best I could get.