Botanicare CAL-MAG Plus Plant Supplement 2-0-0 Formula, 1-Gallon A hydroponic plant nutrient solution that is a proprietary blend of calcium, magnesium, iron, and other nutrients Designed to maximize flower and fruit yield as well as prevent blossom end rot and tip burn Cal-Mag Plus helps plants increase water and nutrient uptake and defends against dry, withered flowers and fruit Use Cal-Mag Plus and see a larger crop yield and healthier plants. Can be used whether you are growing with soil, coco, or hydroponically