What can I do to either slow or stop Algae from growing on my siding?

Like many people who live in wet climates without extreme winters I a plagued by Algae growing on our vinyl siding. While I pressure wash it off reasonably easily its a big project. Classically it grows on the north facing side of the house but last year and this it is beginning to show up on other sides that get sun less than two of three hours a day.

This season its so bad I will need to pressure wash the house twice. There are plenty of products to get moss and algae off roofs but none I have found that seem to address siding.

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