You can see bits of the algae in this image. My tank at one point was covered with it, like dense patches. I bought a sailfin tang which didn't help much, nor did my Atlantic Blue. I decided to become a tang and manually removed as much as I could since they were dense patches they came off easily. I have a micron sock on my intake so it catches whatever's flying around and I hope it catches the spores too since feeding plankton in my tank clogs my micron sock. I have since then lowered my nitrates down to near 0 if not 0, and phospates are undetectable. The growth has gone away in some areas but high light areas still continue to be a problem area. But they do seem to be dying I installed a mesh screen on my intake part to see what's collected when I do nothing, and that gets clogged overnight. I am gradually seeing less and less, so I believe my refugium is finally gaining the upper hand.