When I was fighting dinos,I took every coral that wasnt already dead out of my tank and siphoned out all the dinos I could see.Then I completely unplugged my lights and covered the glass with black trash bags and left it like that for a full 14 days.
During that 14 days.I keep the PH at 8.5-8.6 by dripping kalk 24/7 and using straight limewater for top-offs.
After the 14 days,I did a 75% water change and crossed my fingers.
That was my last resort.If it hadnt of worked,I was going to catch out the fish and pour in a gallon of bleach.