Just sharing my gha outbreak counter strategy. I take out some of the corals n plug off as much gha as possible, re-glue them back. Break up my tank maintenance into twice a week, every mid week siphon accumulated detitus in tank & sump, Every end week change 10% water. Refuce feeding from 5 to 3 times a day, reduce photoperiod from 7 to 5hrs. Change rowaphos every month and daily check sufficient flow is channeling the rowaphos reactor, sometimes too low flow it just stop moving around. Activated carbon change twice a month. Reduce iodine n strontium dosage to min and maintain stable kH, temperature and Calcium. So far its a winning battle after a month.