Have been having issues with different SPS losing tissue over the course of several weeks. Pictured (with lights off) forest fire digi, bonsai acro and purple Stylo. These are all very large colonies so dipping the entire colony is not really feasible but I have clipped off pieces and dipped them without finding obvious AEFW, tank has had some pretty big alkalinity swings over the last few weeks, bouncing between 6.2-8.5 over the course of 10 days. None were very rapid but it would raise or drop an entire point over 4-5 days. Based off the pictures, do you think it's just alkalinity swings or is something else going on? Phosphates we're elevated at one point (above 1) when the alkalinity was closer to 8.5 which I believed caused initial stress. Nitrates always below 5, calcium 450-475 and magnesium 1325-1375
