Calcium Magnesium adds additional calcium, magnesium and iron. It helps to prevent nutrient deficiencies and optimizes plant nutrition. It is well suited for high calcium intake plants. Available in 1 Quart 1 Gallon 2.5 Gallons 5 Gallons 15 Gallons 55 Gallons Refer to feeding schedules for amounts and usage. General/Specific Usage: Hydroponics - Use 5 mL per gallon in your reservoir. Soil/Coco/Other medium - Use 5 mL per gallon everytime you water. Discard any unused mixed nutrients. Notes: Never premix with another product, always add directly to the reservoir. Adjust your pH after adding all your products.