Clean Algae From Driveway Downspouts
A few month ago I ran some flexible piping from a rain gutter and a sump pump onto a gravel driveway. Now there is a black green algae where the water is sent. I'm limited on how I can direct the water.
What can I do to clean up this algae? I'm thinking of using a spray pump and either Clorox outdoor bleach or an "oxygen bleach" mix (though nobody seems to know what oxygen bleach is).