Composite decking materials are made from a combination of wood fibers and plastic. Several manufacturers have been involved in class action lawsuits, largely because consumers claim the wood lookalike harbors mold.
A composite deck is made from a mix of wood and plastic. There are many different brands of composite decking each are a little different better or worse regarding scratch and stain resistance, appearance and durability.
Many choose composite decking for How to Remove Mold From Your Deck. Click this link to read why you should never use Chlorine Bleach to clean a composite deck.
Cleaning algae on composite deck: You'll need to remove what you can of the organism, disrupt its growth, and get rid of its food source at the same time.