Also seems that you guys having issues were dosing more frequently.
I began dosing weekly for 2 months and it caused more problems than in the next 2 months when I was dosing every 3 days, because by then I figured out how to control it.
I realized that the sps became extremely sensitive to small alk changes, so I kept it under tight control. My normal alk was 8.5 and 0.5 dKH swings were enough to burn corals, especially montis.
I dropped the alk to 7.5 and never let it swing more than 0.3. It stopped the burning of sps. I have a Xepta Autobalance and I tested alk 6 times per day.