I've been having random STN/RTN and bleaching on my SPS frags, and none of my corals have been growing well. My green slimer has basically just been sitting there, and this is one of the easier SPS to grow. Even 1 of my zoas closed up, and that's when I really started thinking there is something wrong with my tank. The ICP looks fine without any crazy high metals or contaminants. My big parameters (Alk, Ca, Mag, Nitrate) all checked within range (except my Phosphate is a bit high) and verified on my Hanna/Salifert tests.
Without any obvious issues, I've been doing water changes in the past week to possibly reduce any contaminants. I've also been tweaking my lights since I thought why would the corals bleach. Basically, I've been pulling my hair out and chasing my own tail.
Nothing really worked. So I've just chalked it up to being a newer 6 months old reef, and the system was too immature to be adding so much corals, especially SPS. But the zoas closing really bothered me, as I've lost a few GMK zoas and now my red hornets zoas are closed up for most of the day. This is very strange as zoas should be easy and lighting shouldn't be a problem.