KALIX Calcium/Magnesium is a fully soluble calcium (15%) and magnesium (3%) supplement derived from optimized ratios of calcium nitrate and magnesium sulfate. Use this formulation to boost calcium and magnesium levels during all phases of plant growth. KALIX Calcium/Magnesium can help with treating deficiencies and creating custom tailored recipe solutions. Works in conjunction with all nutrient and feeding programs. 25 Lb bag.