I have a geeen acro in my reef tank, I’ve noticed two small patches of STN. Seems like the cause could be just about anything from what I’m reading. It could be microbial or a flow or ever water chemistry issue. The specific gravity is at 1.024, temp is 78, calcium was 450 the last I tested it and alk was 11. I honestly don’t know the other parameters, my teat kits expired and I haven’t replaced them yet. I use an AI 16 prime
hd. I did try getting a picture but even with the blues off and just whites it’s hard ti see it
hd. I did try getting a picture but even with the blues off and just whites it’s hard ti see it