Originally Posted by BrettT
If it's unpainted aluminum siding and chalky, you can use all sorts of cleaners but you will have to brush every SF then rinse. There is no simple way to get that stuff off. It is a royal pain and doesn't come out looking very good since the siding is so old and a lot of the factory finish will come off with the cleaning. Do a test area first so you know your mix isn't so strong it removes the finish to bare metal. Again, if it has been painted, the cleaning will be easier. You said "old painted" so I still don't know if the siding has been painted.
Its older aluminum siding that has been painted white. I do not want to take off the paint, I just want to clean off the black mold and algea. I have been trying to ask what I should use for downatreaming wash solution. I use a 5 gal. Bucket, can anyone give me a mix ?