A few days ago, I noticed a significant uptick in flashing and that one of my mbunas has contracted a case of popeye. My first thought was, oh my nitrate, nitrite, or ammonia is off. After testing, I was stunned. My parameters are fine. I have 5 ppm nitrate, 0 ammonia, 0 nitrite, 8.4 ph, 13 dgh, and 11 dkh. I recently started dosing with victoria/malawi buffer, so the kh ph and gh were expected, but all of the usual causes of cloudy, puffy eyes and flashing are oddly fine. My test kit is not supposed to expire until 2024. I am planning to do a 2/3 water change today, but I wanted to receive some input on this. I will add some epsom salt today as well. Did I miss something? Any other more obscure things to test? I am even more stressed about this because I will be heading on vacation and I don't want al my fish to be dead when I get back.