Deck & Fence Cleaner.
Removes that silver coloured look on your aged deck, removes and kills moss/spores. Will get your deck looking like new. 
 
Directions:
Put 2 cups into a bucket with 7 Litres of warm-hot water. Mix till fully dissolved and immediately brush over or apply with watering can to the wood being treated.
Keep wet for 20-30 minutes with solution then scrub (with the grain), with a medium- stiff brush. Clean off thoroughly with a soft jet of water. Let dry ready for BBQ season or stain to the desired colour.