🎉 Up to 70% Off Selected ItemsShop Sale
\n
\n

FAQ Section

\n
\n
What is Emerald Harvest Cal-Mag? \n
\n
It is a calcium and magnesium supplement with kelp extract designed to prevent deficiencies, support chlorophyll production, and improve nutrient uptake for healthy plants.
\n
\n
\n
Which sizes are available? \n
\n
Emerald Harvest Cal-Mag comes in 1 qt, 1 gal, 2.5 gal, 6 gal, 15 gal, 55 gal, and 270 gal sizes.
\n
\n
\n
Can I use Cal-Mag in coco coir? \n
\n
Yes, it’s especially recommended for coco coir, which can have inherent calcium and magnesium deficiencies.
\n
\n
\n
Does it support flowering? \n
\n
Yes, by providing calcium and magnesium, it promotes strong stems and cell walls, which supports abundant flowering and fruit development.
\n
\n
\n
Is it safe for hydroponic systems? \n
\n
Yes, Cal-Mag is compatible with soil, coco, and hydroponic systems for consistent nutrient supplementation.
\n
\n
\n
What additional nutrients are included? \n
\n
In addition to calcium and magnesium, Cal-Mag contains kelp extract, providing natural micronutrients and growth-promoting compounds.
\n
\n
\n
When should I apply Cal-Mag? \n
\n
Apply Cal-Mag during vegetative and flowering stages as needed to prevent deficiencies or support nutrient uptake in your growing medium.
\n
\n
\n\n
\n

Specifications \"\"\n

\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Emerald Harvest Cal-Mag\"\"
SKUEMHCMG
NPK Nitrogen (N)2
Dimensions (EA)7.7L x 4.7W x 12.7H
Dimensions (CS)13.0L x 7.9W x 18.8H
Dimensions (PL)48.0L x 40.0W x 61.0H
Shipping Weight10.61 lbs
Barcodes859041005907 (UPC-A), 10859041005904 (GTIN)
Available Sizes1 qt, 1 gal, 2.5 gal, 6 gal, 15 gal, 55 gal, 270 gal
\n
\n
\n
\n
\n

What is included? \"\"\n

\n

It includes:

\n
\n
    \n
  • \n\"\" Emerald Harvest Cal-Mag (1 qt / 1 gal / 2.5 gal / 6 gal / 15 gal / 55 gal / 270 gal)\n
    • \n
  • \n\"\" User Instruction Manual\n
    • \n
\n
\n
\n
\"\"
\n
\n
\n
\n
\n

Warranty Policy

\n

Please check out the manufcaturers website for Warranty related issues.

\n
\n
\n
\n","image":["https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-1.jpg","https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-2.jpg","https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-3.jpg","https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-4.jpg","https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-5.jpg","https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-6.jpg","https://img.greenthumbdepotonline.shop/images/product/emerald-harvest-cal-mag-7.jpg"],"sku":"emerald-harvest-cal-mag","brand":{"@type":"Brand","name":"Green Thumb Depot"},"offers":{"@type":"AggregateOffer","lowPrice":5.93,"highPrice":1924.98,"priceCurrency":"USD","availability":"https://schema.org/InStock","url":"https://greenthumbdepotonline.shop/products/emerald-harvest-cal-mag","offerCount":16}}
Emerald Harvest Cal-Mag
HomeStore

Emerald Harvest Cal-Mag

Emerald Harvest Cal-Mag

Select Size Options
Select Quantity
From $5.93

Original: $16.95

-65%
Emerald Harvest Cal-Mag—

$16.95

$5.93

The Story

Emerald Harvest Cal-Mag

Emerald Harvest Cal-Mag is a premium calcium and magnesium supplement designed to keep plants green, healthy, and productive in any growing medium. By promoting chlorophyll production, activating nutrient-uptake enzymes, and preventing deficiencies, this formula ensures robust growth, abundant flowering, and high yields. Kelp extract adds natural micronutrients, making it ideal for coco coir, soil, or hydroponic systems where extra Ca and Mg are needed.

  • Features & Benefits
  • Product Specifications
  • What is included?
  • Warranty Policy

Key Features of Emerald Harvest Cal-Mag

Emerald Harvest Cal-Mag provides essential calcium and magnesium while supporting overall plant health and nutrient absorption. Its premium ingredients and kelp extract help prevent deficiencies and maintain strong, vigorous crops for maximum yield potential.

  • Supplemental calcium and magnesium for all growing media.
  • Promotes chlorophyll production for healthy, green plants.
  • Activates plant enzymes to improve nutrient uptake.
  • Includes kelp extract for natural micronutrients and plant support.
  • Reduces the risk of calcium or magnesium deficiencies.
  • Supports strong roots, stems, and abundant flowering.

Stronger Plants, Greener Gardens

Emerald Harvest Cal-Mag ensures your crops receive the essential calcium and magnesium needed for strong cell walls, efficient nutrient absorption, and vibrant growth. Its kelp-enhanced formula supports plant metabolism, helping growers achieve lush, productive gardens and heavy harvests.

Why Emerald Harvest?

Emerald Harvest is trusted by professional growers for delivering reliable, high-quality nutrients that support every growth stage. Their 3-part nutrient system allows flexible feeding programs, precision nutrient management, and exceptional harvest results, ensuring growers achieve maximum potential and consistency in every crop.

Why Buy From Us?

At GreenThumbDepot, you're not just another sale to a faceless corporation. You're partnering with a team genuinely invested in your success. Our legendary customer service, combined with a promise of unbeatable prices, sets us apart. We're here for you, always.

Excellent 4.8 out of 5 based on 1,247 reviews
If I could rate 6 stars I would!
If I could rate 6 stars I would! My representative Edouard B. has been shockingly responsive! Like - oh my god - an actual SERVICE oriented company. He's dug into my odd connectivity issues I've been having - and following up in an AMAZINGLY timey manner. No shit. You'll be impressed! (And the price was also unbeatable, quick shipping...it's all PERFECT). Thank you Ed!!
Reviewer
Jim D

Customer service was outstanding great…
Customer service was outstanding great people to deal with they understand your needs and they will do their best to fulfill them there is no way I can complain about them because they are the best help out there.Thanks green thumb depot. I'll definitely order from them again
Reviewer
Glenn Appleton

The machine is doing just what my…
The machine is doing just what my salesman told it would do (I appreciate you Ed thank you) . The machine is what we need for our new business we're starting up, soon to be llc and licensed. We are getting a lot of clients wanting our services. Ed I will be needing more of your products, thank you again.
Reviewer
Freddie

Fantastic
Great prices, fantastic customer service, and mind blowing shipping! Incredible. Will be using again and telling anyone in need.
Reviewer
Kar

←
→

FAQ Section

What is Emerald Harvest Cal-Mag?
It is a calcium and magnesium supplement with kelp extract designed to prevent deficiencies, support chlorophyll production, and improve nutrient uptake for healthy plants.
Which sizes are available?
Emerald Harvest Cal-Mag comes in 1 qt, 1 gal, 2.5 gal, 6 gal, 15 gal, 55 gal, and 270 gal sizes.
Can I use Cal-Mag in coco coir?
Yes, it’s especially recommended for coco coir, which can have inherent calcium and magnesium deficiencies.
Does it support flowering?
Yes, by providing calcium and magnesium, it promotes strong stems and cell walls, which supports abundant flowering and fruit development.
Is it safe for hydroponic systems?
Yes, Cal-Mag is compatible with soil, coco, and hydroponic systems for consistent nutrient supplementation.
What additional nutrients are included?
In addition to calcium and magnesium, Cal-Mag contains kelp extract, providing natural micronutrients and growth-promoting compounds.
When should I apply Cal-Mag?
Apply Cal-Mag during vegetative and flowering stages as needed to prevent deficiencies or support nutrient uptake in your growing medium.

Specifications

Emerald Harvest Cal-Mag
SKU EMHCMG
NPK Nitrogen (N) 2
Dimensions (EA) 7.7L x 4.7W x 12.7H
Dimensions (CS) 13.0L x 7.9W x 18.8H
Dimensions (PL) 48.0L x 40.0W x 61.0H
Shipping Weight 10.61 lbs
Barcodes 859041005907 (UPC-A), 10859041005904 (GTIN)
Available Sizes 1 qt, 1 gal, 2.5 gal, 6 gal, 15 gal, 55 gal, 270 gal

What is included?

It includes:

  • Emerald Harvest Cal-Mag (1 qt / 1 gal / 2.5 gal / 6 gal / 15 gal / 55 gal / 270 gal)
  • User Instruction Manual

Warranty Policy

Please check out the manufcaturers website for Warranty related issues.

Emerald Harvest Cal-Mag - Image 2

Details & Craftsmanship

Every detail has been carefully considered to bring you the perfect product.

Emerald Harvest Cal-Mag - Image 3

Details & Craftsmanship

Every detail has been carefully considered to bring you the perfect product.

Emerald Harvest Cal-Mag - Image 4

Details & Craftsmanship

Every detail has been carefully considered to bring you the perfect product.

Emerald Harvest Cal-Mag - Image 5

Details & Craftsmanship

Every detail has been carefully considered to bring you the perfect product.

Emerald Harvest Cal-Mag - Image 6

Details & Craftsmanship

Every detail has been carefully considered to bring you the perfect product.

Emerald Harvest Cal-Mag - Image 7

Details & Craftsmanship

Every detail has been carefully considered to bring you the perfect product.

Description

Emerald Harvest Cal-Mag

Emerald Harvest Cal-Mag is a premium calcium and magnesium supplement designed to keep plants green, healthy, and productive in any growing medium. By promoting chlorophyll production, activating nutrient-uptake enzymes, and preventing deficiencies, this formula ensures robust growth, abundant flowering, and high yields. Kelp extract adds natural micronutrients, making it ideal for coco coir, soil, or hydroponic systems where extra Ca and Mg are needed.

  • Features & Benefits
  • Product Specifications
  • What is included?
  • Warranty Policy

Key Features of Emerald Harvest Cal-Mag

Emerald Harvest Cal-Mag provides essential calcium and magnesium while supporting overall plant health and nutrient absorption. Its premium ingredients and kelp extract help prevent deficiencies and maintain strong, vigorous crops for maximum yield potential.

  • Supplemental calcium and magnesium for all growing media.
  • Promotes chlorophyll production for healthy, green plants.
  • Activates plant enzymes to improve nutrient uptake.
  • Includes kelp extract for natural micronutrients and plant support.
  • Reduces the risk of calcium or magnesium deficiencies.
  • Supports strong roots, stems, and abundant flowering.

Stronger Plants, Greener Gardens

Emerald Harvest Cal-Mag ensures your crops receive the essential calcium and magnesium needed for strong cell walls, efficient nutrient absorption, and vibrant growth. Its kelp-enhanced formula supports plant metabolism, helping growers achieve lush, productive gardens and heavy harvests.

Why Emerald Harvest?

Emerald Harvest is trusted by professional growers for delivering reliable, high-quality nutrients that support every growth stage. Their 3-part nutrient system allows flexible feeding programs, precision nutrient management, and exceptional harvest results, ensuring growers achieve maximum potential and consistency in every crop.

Why Buy From Us?

At GreenThumbDepot, you're not just another sale to a faceless corporation. You're partnering with a team genuinely invested in your success. Our legendary customer service, combined with a promise of unbeatable prices, sets us apart. We're here for you, always.

Excellent 4.8 out of 5 based on 1,247 reviews
If I could rate 6 stars I would!
If I could rate 6 stars I would! My representative Edouard B. has been shockingly responsive! Like - oh my god - an actual SERVICE oriented company. He's dug into my odd connectivity issues I've been having - and following up in an AMAZINGLY timey manner. No shit. You'll be impressed! (And the price was also unbeatable, quick shipping...it's all PERFECT). Thank you Ed!!
Reviewer
Jim D

Customer service was outstanding great…
Customer service was outstanding great people to deal with they understand your needs and they will do their best to fulfill them there is no way I can complain about them because they are the best help out there.Thanks green thumb depot. I'll definitely order from them again
Reviewer
Glenn Appleton

The machine is doing just what my…
The machine is doing just what my salesman told it would do (I appreciate you Ed thank you) . The machine is what we need for our new business we're starting up, soon to be llc and licensed. We are getting a lot of clients wanting our services. Ed I will be needing more of your products, thank you again.
Reviewer
Freddie

Fantastic
Great prices, fantastic customer service, and mind blowing shipping! Incredible. Will be using again and telling anyone in need.
Reviewer
Kar

←
→

FAQ Section

What is Emerald Harvest Cal-Mag?
It is a calcium and magnesium supplement with kelp extract designed to prevent deficiencies, support chlorophyll production, and improve nutrient uptake for healthy plants.
Which sizes are available?
Emerald Harvest Cal-Mag comes in 1 qt, 1 gal, 2.5 gal, 6 gal, 15 gal, 55 gal, and 270 gal sizes.
Can I use Cal-Mag in coco coir?
Yes, it’s especially recommended for coco coir, which can have inherent calcium and magnesium deficiencies.
Does it support flowering?
Yes, by providing calcium and magnesium, it promotes strong stems and cell walls, which supports abundant flowering and fruit development.
Is it safe for hydroponic systems?
Yes, Cal-Mag is compatible with soil, coco, and hydroponic systems for consistent nutrient supplementation.
What additional nutrients are included?
In addition to calcium and magnesium, Cal-Mag contains kelp extract, providing natural micronutrients and growth-promoting compounds.
When should I apply Cal-Mag?
Apply Cal-Mag during vegetative and flowering stages as needed to prevent deficiencies or support nutrient uptake in your growing medium.

Specifications

Emerald Harvest Cal-Mag
SKU EMHCMG
NPK Nitrogen (N) 2
Dimensions (EA) 7.7L x 4.7W x 12.7H
Dimensions (CS) 13.0L x 7.9W x 18.8H
Dimensions (PL) 48.0L x 40.0W x 61.0H
Shipping Weight 10.61 lbs
Barcodes 859041005907 (UPC-A), 10859041005904 (GTIN)
Available Sizes 1 qt, 1 gal, 2.5 gal, 6 gal, 15 gal, 55 gal, 270 gal

What is included?

It includes:

  • Emerald Harvest Cal-Mag (1 qt / 1 gal / 2.5 gal / 6 gal / 15 gal / 55 gal / 270 gal)
  • User Instruction Manual

Warranty Policy

Please check out the manufcaturers website for Warranty related issues.

Emerald Harvest Cal-Mag | Green Thumb Depot