I had my deck cleaned nice and white last fall, but today it seems to be covered with fungus/mold/algae of some sort from sitting under trees for the winter. Neither Simple Green nor Starbrite Deck Cleaner will get the staining out of the flat white paint. The non-skid areas seem to respond to the Starbrite and too much scrubbing. Surely there's an easier way...no one would own a sailboat if it took this much work every Spring. Anyone have a fix for this short of a flame thrower?