Hydrofarm Grow!T Premium Coco Coir, Loose 1.5 Cubic Foot Bag Superior premium quality, 100% natural coir hydroponic growing medium GROW!T Loose Premium Coco Fiber is a special blend of coir that is buffered, treated, and enriched with micronutrients The strategic addition of just the right amounts of calcium and magnesium actually displaces sodium and excess potassium Its low EC and stable pH make this coir such a supreme hydroponic and soilless medium Based on our testing, we believe it is the best loose coco coir on the market today.