Calcium Magnesium Products (CalMag)

What is Cal-Mag?

Cal-Mag is a calcium and magnesium supplement designed to provide two essential secondary nutrients that support healthy plant development. It is commonly used alongside base nutrients to help maintain balanced nutrition, particularly in coco coir, hydroponic systems and gardens using reverse osmosis (RO) or soft water.

Why use a calcium and magnesium supplement?

• Supplies essential calcium and magnesium for healthy plant growth.
• Supports balanced nutrient uptake throughout the growing cycle.
• Suitable for soil, coco coir and hydroponic gardens.
• Compatible with many popular nutrient programs.
• Available in formulations suited to both hobby and commercial growers.

Choosing the right Cal-Mag product

The best Cal-Mag supplement depends on your growing media, water source and feeding program.

• Hydroponics: Choose a Cal-Mag product designed for hydroponic nutrient programs and monitor EC and pH regularly.
• Coco coir: Calcium and magnesium supplements are commonly incorporated into routine feeding schedules.
• Soil gardens: Use Cal-Mag where additional calcium and magnesium are required, following the manufacturer's directions.
• RO or soft water: Supplementing with Cal-Mag can help restore essential minerals often absent from purified water.

Get the most from your feeding program

For consistent results, pair your Cal-Mag supplement with quality base nutrients and hydroponic additives that complement your growing method. Regular monitoring of pH, EC and watering practices will help create a balanced environment for healthy plant development.

Shop Cal-Mag supplements at Dr Greenthumbs

Browse our Cal-Mag collection to find premium calcium magnesium products for hydroponics, coco and soil gardens. Whether you're correcting deficiencies or building a complete nutrient program, you'll find trusted Cal-Mag solutions to support healthy, productive plants.