I've been battling an unknown algae in my 4 month old 40g reef for 2 months now, and nothing I do seems to make any difference. I have identified it to be lyngbya at this point, it grows in a brownish hair like structure very quickly, almost exclusively in high flow areas. I was doing 20-30% water changes every week and scrubbing it off of the rocks, but it just returns every week. It grows on my rocks and sand, anywhere where there is turbulent flow. I dosed fluconazole over a week ago and it has had 0 impact on the lyngbya whatsoever. Every thread I read about it seems to end in people just scrapping the whole tank, which is something I really do not want to come to. I'm hoping someone out there has the answer to beat this stuff!
When it first showed up my no3 was around 6-8 and po4 was .02. Now it sucks up nutrients in the tank and my no3 and po4 will bottom out if not dosed. Nitrate seems to stay in the 3-5 range for a bit once dosed, but po4 drops right back down to 0 overnight even with dosing the equivalent of .06/day. I'm lost as to what to do here, my corals have all paled out from lack of nutrition and I can't keep nutrients up, but this stuff just continues growing. It even grows on my glass every few days, and my back wall becomes covered in it. Filtration is just a skimmer and filter sock changed every 3 days. I'd really appreciate any advice from someone who has dealt with this stuff! And as I said, I have scrubbed the rocks countless times and it just comes right back, so a rip clean is not the answer here. Attached picture is from 2 rocks with very high flow at the top of my tank.
When it first showed up my no3 was around 6-8 and po4 was .02. Now it sucks up nutrients in the tank and my no3 and po4 will bottom out if not dosed. Nitrate seems to stay in the 3-5 range for a bit once dosed, but po4 drops right back down to 0 overnight even with dosing the equivalent of .06/day. I'm lost as to what to do here, my corals have all paled out from lack of nutrition and I can't keep nutrients up, but this stuff just continues growing. It even grows on my glass every few days, and my back wall becomes covered in it. Filtration is just a skimmer and filter sock changed every 3 days. I'd really appreciate any advice from someone who has dealt with this stuff! And as I said, I have scrubbed the rocks countless times and it just comes right back, so a rip clean is not the answer here. Attached picture is from 2 rocks with very high flow at the top of my tank.