Emerald Harvest Cal-Mag, 55 gal

Emerald Harvest Cal-Mag – Calcium-Magnesium Supplement with Kelp, 55 Gallon

Emerald Harvest Cal-Mag is a calcium and magnesium supplement designed for use with any base nutrient program in any growing medium. Calcium and magnesium deficiencies are among the most common nutrient problems in hydroponic and soilless production, particularly in coco coir, which has a natural cation exchange capacity that can bind and sequester calcium and magnesium from the nutrient solution before they reach the plant. Cal-Mag provides additional calcium and magnesium to compensate for this demand, maintaining adequate levels in the root zone for plant uptake.

Cal-Mag contains kelp as a secondary ingredient. Kelp is a natural source of plant-beneficial compounds including trace nutrients and growth-promoting compounds. Calcium in the formulation supports cell wall integrity and root tip development, which contributes to plant structural strength and healthy shoot growth. Magnesium is the central atom in the chlorophyll molecule — adequate magnesium ensures the plant can synthesize sufficient chlorophyll to capture light energy efficiently. Magnesium is also required to activate the enzymes that facilitate nutrient uptake in root cells, making it important not just for chlorophyll production but for the plant's overall ability to take up nutrients.

Key Features & Benefits

• Calcium Supplement — Supports cell wall integrity, root development, and overall plant structure.
• Magnesium Supplement — Central to chlorophyll synthesis and enzyme activation for nutrient uptake.
• Contains Kelp — Natural kelp source of trace nutrients and growth-stimulating compounds.
• For Any Growing Medium — Especially important in coco coir, which has high calcium-magnesium demand.
• Reduces Deficiency Risk — Supplemental Ca and Mg prevent the deficiency symptoms common in coco and other demanding media.
• Promotes Chlorophyll Production — Adequate Mg maintains green, vigorous foliage through all growth phases.
• 55 Gallon Size — Drum quantity for large commercial operations with high Cal-Mag consumption.

Who Should Use Cal-Mag

Cal-Mag is for growers using coco coir, rockwool, and other soilless or hydroponic media where calcium and magnesium deficiencies are a common challenge. It can also benefit soil growers running reverse-osmosis or soft water — low-mineral water supplies can be deficient in calcium and magnesium, and Cal-Mag supplements these minerals to standard levels.

Calcium and Magnesium in Coco Coir: Why Extra Supplementation Is Required

Coco coir is produced from the fibrous husks of coconuts. During processing, the coir is often rinsed and buffered to remove natural sodium and potassium salts, but coco coir still retains a significant cation exchange capacity — the ability to bind positively charged ions. Calcium (Ca2+) and magnesium (Mg2+) are both positively charged ions that are readily bound by coco coir's cation exchange sites. When a grower feeds through coco coir with a standard hydroponic nutrient solution, the coir can pull calcium and magnesium out of the solution and bind it in the medium, reducing the concentration available to the plant's roots. Buffering the coco coir before first use and consistently supplementing with Cal-Mag throughout the grow are the standard practices for managing this issue.

Frequently Asked Questions

Why do coco coir growers need extra calcium and magnesium?

Coco coir's cation exchange capacity binds calcium and magnesium from the nutrient solution, reducing what's available to plant roots. Cal-Mag supplements these elements to compensate.

Does Cal-Mag work in soil?

Yes. Cal-Mag is beneficial in soil when the water source is low in calcium or magnesium — common with RO or soft water supplies.

What is kelp used for in Cal-Mag?

Kelp provides a natural source of trace nutrients and plant-beneficial compounds as a complement to the primary calcium and magnesium supplementation.

Why is magnesium important for chlorophyll?

Magnesium is the central atom in the chlorophyll molecule. Without adequate magnesium, plants cannot synthesize sufficient chlorophyll, which reduces light capture and overall vigor.

Can Cal-Mag be used with any nutrient line?

Yes. Cal-Mag is designed as a universal supplement compatible with any base nutrient program.