Restore a Discolored Deck
A quick fix you can do yourself.
Is your once beautiful deck now a greenish-black eyesore? The fast and best solution, according to the experts, is to clean your deck with an oxygen bleach, a bleach that doesn’t contain chlorine. Many brands of the bleach are available from online sellers and home improvement centers, and any oxygen bleach should do the trick.
Mix the product in water according to label directions and apply it liberally to all the deck surfaces. Leave it on for ten minutes. You may need to reapply it to vertical surfaces a time or two, since it will run off. Lightly scrub the surfaces with a push broom; then rinse them with a garden hose.