Sunshine Mix #4 High Porosity Growing Mix is specifically designed for the hydro market with increased amounts of Perlite for improved porosity. Recommended for indoor growing. May be used for all types of containers and crops. Contains Canadian sphagnum peat moss, coir, perlite, lime, wetting agent and mycorrhizae Provides superior drainage Contains resilience, may improve resistance to wilting Expands up to 2x