PuurCalMag: Organic Calcium and Magnesium for Deficiency Prevention

PuurCalMag is an OMRI-certified organic calcium and magnesium supplement chelated with natural acetic acid for rapid plant absorption. It prevents the most common nutrient deficiencies in modern cultivation—especially critical for coco coir, RO water systems, and LED grows where calcium and magnesium demand exceeds what base nutrients provide.

The Science Behind PuurCalMag

Why Calcium Matters

Calcium plays structural and signaling roles throughout the plant:

• Cell Wall Structure – Calcium pectate "glues" cell walls together, providing structural integrity
• Cell Membrane Function – Calcium maintains membrane permeability and nutrient transport
• Root Development – Root tip cells require calcium for division and elongation
• Stress Signaling – Calcium ions act as secondary messengers in stress response pathways
• Enzyme Activation – Several enzymes require calcium as a cofactor

Critical fact: Calcium is IMMOBILE in plants. Once deposited in tissues, it cannot be redistributed. This means continuous supply is essential—plants cannot move calcium from old leaves to new growth.

Why Magnesium Matters

Magnesium is the central atom in chlorophyll and activates numerous enzymes:

• Chlorophyll Production – Every chlorophyll molecule contains one magnesium atom at its center
• Photosynthesis – Beyond chlorophyll, magnesium activates enzymes in the Calvin cycle
• Energy Transfer – ATP (cellular energy) requires magnesium for activation
• Protein Synthesis – Ribosomes need magnesium to function
• Phosphorus Uptake – Magnesium facilitates phosphorus absorption and transport

Key difference: Unlike calcium, magnesium IS mobile. Deficiency symptoms appear on OLD leaves first as the plant moves magnesium to new growth.

Acetic Acid Chelation

PuurCalMag uses organic acetic acid (from fermentation) as a natural chelating agent. Chelation keeps minerals in plant-available forms by:

• Preventing precipitation with phosphates and sulfates
• Maintaining availability across pH ranges
• Enabling absorption through root membranes

This organic chelation provides fast uptake while maintaining OMRI certification.

When You Need PuurCalMag

Situations Requiring Cal-Mag Supplementation

1. Growing in Coco Coir

Coco coir has a high cation exchange capacity (CEC) with strong affinity for calcium and magnesium ions. The coco fiber essentially "steals" these nutrients from solution before plants can absorb them. Even nutrient solutions with adequate Cal-Mag will show deficiencies in coco unless supplemented.

2. Using RO or Soft Water

Reverse osmosis and naturally soft water lack the dissolved minerals present in tap water. While this provides a clean starting point, it also means zero calcium or magnesium contribution from your water source. Supplementation replaces what's missing.

3. Growing Under LED Lighting

LED lighting drives faster photosynthesis and growth rates than HPS or fluorescent lights. This increased metabolic activity raises calcium and magnesium demand beyond what base nutrients supply. LED growers consistently report more Cal-Mag issues than those using other lighting.

4. Fast-Growing or Heavy-Feeding Genetics

Vigorous cultivars with rapid growth rates consume calcium and magnesium faster than average. If you're growing high-yielding genetics, prophylactic Cal-Mag supplementation prevents deficiencies during peak growth phases.

Application Rates

Standard Rates by Growing Situation

When to Apply

• Add PuurCalMag EARLY in the mixing order—right after base water
• Apply consistently from seedling/clone through harvest
• Don't wait for symptoms—prevention is more effective than correction

Identifying Deficiency Symptoms

Calcium Deficiency

• Location: NEW growth (tops, newest leaves)
• Appearance: Brown spots, necrotic patches, distorted/curled leaves
• Progression: Leaf tips and edges affected first, may curl upward
• Root symptoms: Stunted, brown root tips
• Other signs: Weak stems, blossom end rot in fruiting plants

Magnesium Deficiency

• Location: OLD growth (lower leaves) first
• Appearance: Interveinal chlorosis—yellowing between veins while veins stay green
• Progression: Moves upward as deficiency worsens
• Late stage: Leaves become crispy and fall off
• Other signs: Reduced vigor, pale color overall

Mixing Instructions

Mixing Order in PuurOrganics System

1. Start with water at room temperature
2. Add Armadillo Armour (if using silica—always first)
3. Add PuurNitro
4. Add PuurPhos
5. Add PuurK
6. Add PuurCalMag (after NPK nutrients)
7. Add PuurBalance
8. Add Sticky Bandit (if using)
9. Check and adjust pH
10. Add Monkey Juice (if using—always last, after pH)

Note for RO/soft water: Pre-mix PuurCalMag in a separate container with a small amount of water, then add slowly while stirring to prevent calcium precipitation.

Compatibility

Compatible Products

• All PuurOrganics products (PuurNitro, PuurPhos, PuurK, PuurBalance)
• Cronk additives: Sticky Bandit, Monkey Juice, Bud Booster, Armadillo Armour
• Organic amendments and teas
• Beneficial microbes

NOT Compatible

• Cronk Classic Line (Micro, Grow, Bloom) – Use standard CalMag 2-0-0 instead
• Cronk Bonnie & Clyde – Use standard CalMag 2-0-0 instead
• Other synthetic base nutrients

Frequently Asked Questions

What's the difference between PuurCalMag and regular Cronk CalMag?

PuurCalMag is OMRI-certified organic, using acetic acid chelation from natural sources. Regular Cronk CalMag uses synthetic EDTA chelation for maximum stability. Both deliver calcium and magnesium effectively—PuurCalMag for organic grows, regular CalMag for conventional grows. They are NOT interchangeable between systems.

Why do coco coir growers need PuurCalMag?

Coco coir has a high cation exchange capacity that preferentially binds calcium and magnesium, removing them from nutrient solution before plants can absorb them. This creates deficiencies even when base nutrients contain adequate Cal-Mag. PuurCalMag provides extra calcium and magnesium to compensate for coco's binding effect.

Should I use PuurCalMag with every feeding?

In most situations, yes. Calcium and magnesium deficiencies are cumulative—by the time symptoms appear, the plant has been stressed for weeks. Consistent supplementation prevents problems before they start. This is especially important in coco, with RO water, or under LED lighting.

Can I use PuurCalMag with Cronk Classic Line nutrients?

No. PuurCalMag is designed exclusively for the PuurOrganics system. For Classic Line or Bonnie & Clyde grows, use standard Cronk CalMag 2-0-0 instead. Mixing organic and synthetic systems can cause compatibility issues.

Storage and Handling

• Store in cool, dark location
• Keep bottle sealed when not in use
• Shake well before each use
• OMRI Listed for certified organic production

Need Help?

Our grow support team is here to help you get the best results with PuurCalMag and the complete PuurOrganics system. Contact us at [email protected] or visit our Grower's Resource Center for feed charts and growing guides.