GHA on GSP rock

[Nigel35]

Have a large rock of GSP and some algae which I believe to be green hair, has started to take over some of the rock and the polyps are receding. the rock is key to the structure of the aquascape so I won't be able to remove rock and do a peroxide dip etc. should I just go for manual removal or what?

 

[Yates273]

You can try to dilute a 50/50 mixture of peroxide amd water use a little squirter and squirt on algae. I did this for my Monti and within a day the algae was gone.