Listed by the Organic Materials Review Institute (OMRI), coconut based Sunleaves Coir Bricks and Blocks are derived from an abundant, renewable resource that retains air and moisture incredibly well. Great for amending soil and soilless mixtures. Piece Coir is a sustainable alternative to peat which takes several hundred years to develop. Piece Coir can be used as a soil additive to increase aeration and water retention or used as a base in soilless mixtures and hydroponics. Sunleaves Classic Coir is finely shredded coir material compressed into bricks and blocks: a preferred choice among African violet enthusiasts. Piece Coir Bricks and Blocks feature larger mulch-type coir chunks and chips for greater root penetration, making them ideal for hydroponics gardening. Coir bricks expand to approximately 1/3 cubic foot when soaked in water while the larger blocks expand to an impressive 2.5 cubic feet. 40-liter bag ofchunky, loose-fiber Piece Coir is ready to use and requires no soaking. Piece Coir is a sustainable alternative to peat which takes several hundred years to develop. Piece Coir can be used as a soil additive to increase aeration and water retention or used as a base in soilless mixtures and hydroponics. This product is listed by the Organic Materials Review Institute (OMRI).