GSP coral not opening after GHA attack

[HumbleAsianReefer]

Hello everyone. I think i’m winning against GHA, been fighting it for over a month. Everything in my tank looks fine for now except for my GSP which is sticking on my backwall, still covered with GHA. I did clean it with soft toothbrush every few day, but now it won’t open anymore. I guess it didn’t survive against GHA. Will it recover or i just need to give up on them? Small part of it is still okay but it’s losing colour (it more to brownish i guess)

10 gallon nano
Canister filter (brightwell xport cube no3 & po4)
Protein skimmer
HOB Algae Turf Scrubber
Live Phyto dose 3-4 times per week (
Daily Dose AF Power Elixir (after lights out)

Salifert testkit
no3: 5
Po4: 0.03
Sg: 1.026
Kh: 9
Ca: 420
Mg: 1350
Ph: 8.0-8.5 (using prodac testkit)

 

[Timfish]

Don't give up on the gsp but brushing it frequently can be worse than the gha. I'wouldn't brush them more than once a week. FWIW, siphoning out the algae is vetter than brushing it off. GHA puts a lot of bad DOC into the water and brushing it off only facilitates it.