Emerald Harvest 723950 Cal-Mag Calcium-Magnesium Supplement, 0.95 L Keep your plants productive and Green with cal-mag, a calcium and magnesium supplement from emerald harvest Containing top-quality ingredients, cal-mag is designed to nourish crops with extra calcium and magnesium and create the right conditions for abundant flowering and a heavy yield This is especially important when growing in some Media, such as coco coir, but any garden can benefit Use cal-mag as a supplement to a base nutrient Series for guaranteed professional results