As you might know, the coco coir medium naturally attracts and binds to calcium and magnesium. This means your average nutrients will have a greater percentage of their Ca and Mg bound to the growing medium and not transported to your plants (where you want them)-potentially starving your precious crops. That's why this specially formulated Coco Coir bloom booster accounts for the high levels of potassium already present in Coco Coir so you avoid any possibility of potassium toxicity.