I’ve had my 55 gal marine tank for over 2 yrs now. I have a small cluster of corals, 1clownfish, 1 angelfish, 1 6 line wrasse, 1 yellow tail damsel, and a lawnmower blenny. My water parameters are all good. I thought phos might be the culprit but last test showed 0.25. I do a 15% water change every 2 weeks with R0 bottled water. I have 2 filters - one canister and 1 hang on, a protein skimmer and a uv sterilizer connected to my canister filter. I cannot for the life of me correct the over abundance of brown algae. I’ve added phosphate controlling media to my canister filter along with charcoal. I’ve even tried having lights off for days. Lights are LEDs. Please help! Sherry