Grow More's Mendocino Producer's Choice line of fertilizers are the most advanced powders we've ever created. They are 100% water soluble formulas containing a properly balanced mixture of all essential plant nutrients with quality-enhancing elements; calcium, magnesium, DTPA/EDDHA Iron, carbohydrates, amino acids and no artificial dyes or colorings. This Mendocino line provides highly efficient, performance nutrients as a standalone base nutrient or as a vegetative and bloom stimulant. For use in soilless, hydroponic, organic soils and coco coir systems. Made especially to work with Rock Wool.