How do I get rid of this green stuff on brick?

[Tryeng]

Not AiBU, apologies. Posting for traffic.

Have my first viewing for house (been on market for 2 months).

How do I get rid of green stuff on brink in alley way? Any miracle product? Have chucked a bleach solution on plus white vinegar but no luck

I have one day to focus on outside and one to focus on inside.

Would a power washer make light work of it?

On Amazon etc plus in most diy stores this or similar brand.

It depends, is it organic like algae or is it salts that have leached out of the bricks? Organic and some sort of fungicide should work but if its salt then giving a good scrub with water might help.