Gold Label HydroCoco 80/20 80/20 is 80% HydroCorn and 20% Coco with added mycorrhizae. The sodium and chloride contents are extremely low for a coco substrate, ensuring a stable behavior throughout the use. Mixed with 80% Gold Label Special Mix HydroCorn which is the substrate of choice for the professional hydroponics grower around the world. Don't settle for inferior products containing heavy metals or other contaminates. Now you can grow like the pros with the substrate that was specially developed for serious gardeners growing heavy feeding plants.