I wish to thank you for this wonderful product.Yesterday, I cleaned my deck, either Trex or TimberTech, with Corte Clean and was amazed at how well it removed the mold spores (black spots) on the surface. What is the shelf life for this product? (Approx. 5 Years if stored in a cool, dry place with the lid securely fastened) I am ready to order more if it can be stored for a period of time . Thanks again for this awesome product. Raleigh, N.C.