I was going to mention the white channel in his light settings, as well as the greens. Reducing them and the overall photoperiod schedule should help with the battle as well.From the pictures i can´t rule out that this is not a cyanobacteria. It for sure looks like something from the cyanobacteria world - Calothrix, Lyngbya or similar genus. This can also explain why your algae eaters pass away - many genus, species or strains of cyanobacteria are toxic. The way to defeat these photosynthetic bacteria is IMO to mechanical remove as much as possible and rise the NO3 up to around 2 - 4 ppm - PO4 should be around 0.05 - 0.1 ppm. You maybe need to mechanical clean many times because this is a hard struggle. As you see - my advises contradict the others in this thread and are based on that it is indeed a cyanobacteria - not an algae. Try to establish if it is an algae or a cyanobacteria. I do not think it is a GHA but I can be wrong - it has happens before.
During the struggle - go down in light intensity for a while
Sincerely Lasse
Perhaps a 48hour blackout would be beneficial as well? And maybe just blues for a few days following?





