Cant get rid of GHA

[glb]

I had a big problem with gha in my 10 gallon I had bought rocks used from a torn down system not sure if there's such thing as phosphate pockets but I took out all of my rocks added some new ones while my tank is still kind of new I just have a clownfish it recycled and everything seems fine my corals are all good just goin through the brown algae phase in the cycle

I had a huge algae outbreak after a crash and I think the excess phosphates leached into the rock. The phosphates are fine now with a phosban reactor but I still have the gha, just not as bad. It's gradually getting better. My guess is that the rocks are feeding it with phosphates and they will eventually stop. The phosphates in the water were 0 so that's why I think it's coming from the rocks.