So here's some more details behind my question. Tank is A 125 SPS dominated. 6 years old 115 total gallon estimated
No3 is zero
Po4 is .02 or below I have a super high flow gph. Guessing around 96x
1 mp40 qd
1 TUNZE 6105
2x TUNZE 6095
Sicci syncra 5.0 I think or 4.0 don't remember
I have great color on my corals and good growth.
I have no algae what so ever except this green stuff that makes my sand hard on the sand bed on the surface.
My bulbs were replaced 7 months ago ATI 6 x 80
I feed 1-2 x a day Frozen mysis rinsed in RO
Pellets 1 x a week if that
3x a week1 sheet of nori
Water changes 12-15% every 2 weeks
Turkey Bastor on rocks weekly to loosen detritus.
I have no clue how rid this stuff. Started weekly water changes 3 weeks ago to help. Syhponed out my overflows and sump. Change filter socks every 3-4 days
Truth is I don't even know what this still is? Cyano, spirulina, algae, who knows. No much on the internet.
Thanks for reading!