Good luck with the battle. I battled GHA for the better part of last year and it was not fun.Alright, quick update. It's been over a month since the dinos outbreak. UV directly in display fixed this in about 4 days. My nutrients stayed around no3 8-10 and no4 around .1 during this time; however, gha took over completely.
You can see little man here sleeping in a nest of gha.
I added a plethora of snails, a pincushion urchin, black spine urchin, and pencil urchin. The urchins do massive damage to the algae but was not enough.
My fish order came in from Dr. Reef, just in time. I added a Purple Tang, Desjardin Sailfin Tang, and a Convict Tang. I asked for all 3 to be about the same size; however, the purple was about 2 inches, the Convict was 4 inches, and the sailfin was pushing 6 inches. The Convict came in spinning in circles in the bag and did not make it through the night. Dr. Reef has already refunded the tang and the wrasse that did not ship. YMMV with fish sizes. The sailfin is now king of the tank.
I have been manually removing gha every other day, changing filter floss daily, reduced lighting, reduced feeding, and began dosing microbacter clean. I'm prepared for a long battle ahead. It is starting to slow up, but it just comes back so fast.