I have a new tank build, up since March (6 mos): 75 gal DT, 20 gal sump w/ Kessil H80 over good growing chaeto in refugium, Vertex 130 skimmer, BRS GFO/Carbon reactor, 2 x Tunze powerheads, RODI water w/ TDS<1 ppm, 2 x Kessil A360 @ 12.5 hrs a day (~4 hrs @ 100% intensity), and Iwaki external return pump at ~ 10x /hr turnover.
T=77-79 deg, ph=8.0-8.3, ORP=440-490, SG=1.025, Alk=8.0-9.0, Ca=440 ppm, Mg~1350 ppm, NO3~0-2 ppm, PO4=0 ppm.
7 x small fish, 8 x trochus snails, 1 fighting conch, 4 x nassarius snails, ~10 hermit crabs, 3 x emerald crabs, 2 x peppermint shrimp, handful of mixed corals.
A month ago I started increasing the light intensity from peak of 60% intensity to 100% intensity and got a cyanobacteria bloom I can't get rid of. I keep beating it back, dislodging with a baster and removing as much as possible during 25% water change. It keeps coming back. I'm trying to avoid using a chemical slime remover, but worried if I don't keep it in check or defeat it it will take over.
What I can't figure out is: what is driving the cyano? NO3 and PO4 are at or near 0, photo period is normal, I don't over feed, and other water parameters are good.
Any ideas/thoughts before I take the chemical option? Thanks in advance for your insights.
T=77-79 deg, ph=8.0-8.3, ORP=440-490, SG=1.025, Alk=8.0-9.0, Ca=440 ppm, Mg~1350 ppm, NO3~0-2 ppm, PO4=0 ppm.
7 x small fish, 8 x trochus snails, 1 fighting conch, 4 x nassarius snails, ~10 hermit crabs, 3 x emerald crabs, 2 x peppermint shrimp, handful of mixed corals.
A month ago I started increasing the light intensity from peak of 60% intensity to 100% intensity and got a cyanobacteria bloom I can't get rid of. I keep beating it back, dislodging with a baster and removing as much as possible during 25% water change. It keeps coming back. I'm trying to avoid using a chemical slime remover, but worried if I don't keep it in check or defeat it it will take over.
What I can't figure out is: what is driving the cyano? NO3 and PO4 are at or near 0, photo period is normal, I don't over feed, and other water parameters are good.
Any ideas/thoughts before I take the chemical option? Thanks in advance for your insights.