This stuff is black and fuzzy, hairy, Exactly like hair alge except black, I've had a lot of cyano in my day, But never seen, nor did I know it is black. Also isn't cyano caused by excess nutriants. This tank was set up 2 1/2 months ago useing RO water. And never put anything else in there except the snail a couple weeks ago. Also when I tested the water the other day. It tested
nitrate 0
Ammonia 0
PH 8.2
nitrite 0
Phos 0.1
KH 8.0
ALK 2.86
cal 450
salinity 1.024
temp 82.
I don't know much, but I thought those test results were good.
I have a seaclone running on it, It is pulling about 1/4 cup every 4 days. and a emperor 400, and emperor 280, and a powerhead for water circulation. I had the diatom explosion, and about a week later it all disapeared. Then the other day, This junk just popped up. Why would the tank need to go thru another cycle? Especailly one this bad. Like I said nothing was added. no chems. no food.