Oh no! Aluminum siding!

Hello guys. New to the power washing world and already ran into a crummy job. I washed this aluminum sided apartment building for a friend/customer. Used standard SH and elemonator mixed to spec's. Used Gutter Grenade on the gutters as well.

House wash got the algae and dirt off great, but this place has been neglected for years and has some deep stains going on. Only thing that removed the stains was BioClean which is a mild abrasive. Too labor intensive and probably takes the paint with it.

Any thoughts on attempting to clean this? Besides just walking away

You can give the customer the added increase in price to use the Bioclean or let him know that it needs to be painted

you sure you mixed it strong enough?

I agree with Steven crank the mix up and my thoughts would be keep the gutter cleaner far away from that house and gutters.The metal is showing on the gutters there to far gone to clean.

looks like corrosion between the alum and the environment. It is very common in the north where any salt is used for deicing the roads. When the salt dries or when the vehicles drive through it becomes airborne and attaches to the homes. When the paint is thin or fails in small areas like that it will cause the surface to corrode. (just like truck rails) If you Two step it and most of it should go away.