[stancfii]

I’ve been pulling my hair out trying to figure out the root cause of STN I’ve been fighting since the summer. Alkalinity is stable at 8.0, calcium at 400, Mg 1360, nitrates may be detectable at 1 on occasion using Red Sea, phosphate 2ppb with Hanna ULR. Some SPS frags and colonies continue to grow at a slow rate, while others keep fighting STN... and they are in the same places they’ve always been. I’ve changed all RO filters, heater (it was old), new circulation pumps, test kits, everything I can think of other than my return pump (eheim) and skimmer pump (jebao). I dose ALK via Randy’s recipe via BRS dosing pump, and Ca is Reef Fusion that I dose once or twice a week as I test for it. Prices like my green slimer go bottom up, but I have a red dragon that has started going top down. My only thoughts are bad salt or too many trace elements since the reef fusion has several in it. I switched to Reef Crystals earlier last year which may have been around the time this started, but I can’t really remember. Before that I was using Fritz RPM and everything was growing well and colors were great, but not convinced the salt is the issue since some of the finest tanks I’ve seen use RC. Should I try a Triton test?? Lights are 3 Radiums and 2 VHO actinic, tank is standard 180. I run carbon through a reactor and rowaphos passively.

Thanks for the input.