Help - Been Asked To Pressure Wash Algae Off Brickwork

I've been asked to pressure wash the bottom three courses of bricks around a local block of flats as in places there is a lot of algae and moss accumulating due to it not getting much direct sunlight.

Questions:

I have a Nilfist 1.2 pressure washer and lance so I think this would be ok as I don't want to rent/buy any equipment. Opinions?

Should I pretreat the walls to loosen/kill the algae before pressure washing? If so what with?

Can I damage anything do you think. The pointing looks ok to me and he bricks solid?

How much should I charge? By the metre?

All advice welcome as I am meeting the building manager Friday so would like I be a bit more clued up.

Thanks in advance,

Adrian.

what spec is the washer , also price wise is either by the meter or price per hour , if you pressure wash the area first and after that spray chloras on the area or mossgo and your sorted

The pressure washer is 110 bar & 6 litres per min. Does ok on decking, paving slabs etc. I don't want anything too powerful and damage the bricks/mortar. Thanks for the Mossgo tip.

that wont do damage , if you can source chloras locally its way cheaper than the mossgo , chloras is usually sold in farmers co ops or suppliers

Thanks for all the help Mr Shine - will go look for some Chloras locally & when I meet this guy at least I now know a bit about what i'm talking about!