Hi
The pictures below show a wall which we tried to clean this morning. We used the following, 1st we tried pressure washing with water, then we applied ubic 2000 left to soak and then rinsed off, then we tried Amtech Wall Cleaner and rinsed that off. We then tried pure water through a waterfed pole.
We managed to remove by pressure washing the green mould/Algae on the surface but it left a green stain behind it.
Any help/advice on what chemical to apply would be appreciated.
Is there anything that can remove this stain as we used up to 200 BAR with no results.