You know that, like developing children, your plants need a steady supply of calcium and magnesium for strong and healthy growth. But even advanced growers often overlook another element their high-value crops need: specific forms of iron in exacting ratios. If you're using our base nutrients, you're already getting the correct amounts of these vital elements. But if you're using base nutrients made by other companies, your crops could be deficient, leading to stunted growth and yellowing leaves. In that case, you need Sensi Cal-Mag Xtra, the only cal-mag additive formulated with the exact Ca, Mg, and Fe ratios unique to the plants we grow. It also contains optimal amounts of the diverse micronutrients your plants crave.