
PuurCalMag Organic Calcium + Magnesium Supplement
Strength starts here. PuurCalMag delivers fast-absorbing calcium and magnesium to prevent common deficiencies and supports strong growth from roots to canopy. Clean, effective, and built for balanced performance in any system.
Organic Calcium + Magnesium Supplement
Build structure. Prevent deficiencies. Grow strong from the roots up.
PuurCalMag is your plant’s structural support system. Designed to correct and prevent two of the most common deficiencies in cultivation—calcium and magnesium—this formula delivers clean, organic nutrition to reinforce growth at every stage.
Sourced from the earth, PuurCalMag combines calcium derived from mined limestone and magnesium extracted from deep-earth brine, then binds them with organic acetic acid (yes, vinegar!) to create a fast-absorbing, sediment-free formula. The result is a clean, highly available Cal-Mag supplement that keeps your plants growing strong—without clogging lines, leaving residue, or adding unnecessary salts.
🌍 Built with Sustainability in Mind
PuurCalMag is made using natural mineral sources and organic acids, not synthetic chelators or mined salts. Its ingredients are selected for purity, bioavailability, and low environmental impact.
• Clean-source calcium and magnesium
• No harsh preservatives, dyes, or fillers
• Safe for soil biology and regenerative practices
✅ Why Growers Love It:
• Prevents calcium and magnesium deficiencies in all grow systems
• Strengthens stems, roots, and cellular structure
• Improves nutrient transport and photosynthesis
• Fully soluble and sediment-free – won’t clog emitters or drip lines
• Clean, organic, and eco-conscious – no synthetic chelates or harsh additives
Whether you’re running a commercial system or a few pots at home, PuurCalMag is essential for maintaining healthy structure, maximizing uptake, and avoiding growth-limiting deficiencies.
🌿 Part of the Complete PuurOrganic Feed Program
PuurCalMag is a critical supplement to the Cronk Nutrients PuurOrganic Feed Program, ensuring that your base nutrients have the foundation they need to perform.
Use it alongside:
• PuurNitro – for lush green vegetative growth
• PuurPhos – for root development and flowering
• PuurK – for late-stage density and stress resistance
• PuurBalance – to enhance uptake and deliver complete micros
Together, these products form a fully customizable, clean and complete nutrient system that puts you in control of your plants’ health—without synthetic overkill or bottle clutter.
Safe for All Plant Types & Grow Mediums
At Cronk Nutrients, we pride ourselves on creating fertilizers that are compatible with a wide range of plants and growing mediums.
🌎 Compatibility
PuurCalMag works in all growing systems and media, including:
✔️ Soil
✔️ Soilless mixes (Pro-Mix HP, peat blends)
✔️ Coco coir (Pro-Mix CX, buffered coco)
✔️ Deep Water Culture (DWC)
✔️ Drip irrigation and automated systems
✔️ Living soil and organic no-till beds
✔️ Foliar spray applications
Great for all plant types, including:
🌿 Leafy greens, vegetables, and herbs
🌸 Flowering ornamentals and greenhouse crops
🌱 Potted plants and houseplants
🌾 Turf, lawn, and landscape
🌳 Fruiting trees, vines, and shrubs
Directions
SHAKE BEFORE USE
Dilute the suggested amount as per the chart on the back of the bottle into at least 1 litre of water. Apply once per week or every other watering. Safe to use in conjunction with any other nutrients. Use for the majority of the plant's life.
🌱 How to Use
Soil Application:
- Use 1–2 mL per 1 L or 4–8 mL per gallon
- Apply once per week or as needed
Hydroponic & Soilless Systems:
- Use 1.5–2.5 mL per 1 L or 6–10 mL per gallon
- Add to your reservoir weekly or with every feeding
Foliar Spray:
- Use 10–15 mL per 1 L or 38–57 mL per gallon
- Spray to the point of runoff throughout the grow as needed
🌿 Part of the Complete PuurOrganic Feed Program
PuurCalMag is a critical supplement to the Cronk Nutrients PuurOrganic Feed Program, ensuring that your base nutrients have the foundation they need to perform.
Use it alongside:
- PuurNitro – for lush green vegetative growth
- PuurPhos – for root development and flowering
- PuurK – for late-stage density and stress resistance
- PuurBalance – to enhance uptake and deliver complete micros
Together, these products form a fully customizable, clean and complete nutrient system that puts you in control of your plants’ health—without synthetic overkill or bottle clutter.
Conversions: 1 Teaspoon = 5mL | 1 Tablespoon = 15 mL | 1 Ounce = 30mL | 1 Cup = 240 mL
Guaranteed Analysis
Calcium (Ca)............4.00%
Magnesium (Mg) …..1.65%
Derived From: Calcium Carbonate, Magnesium Chloride
Safety Data Sheet
CLICK HERE for a copy of Cronk Nutrients PuurCalMag SDS
Shipping
Cronk Nutrients' online store ships all over Canada and the United States from Canada & the United States. If your country isn't a standard option, please contact us and we can get a shipping quote. We offer free shipping on any order in North America over $125* We ship via UPS, Purolator, FedEx, Canada Post or from our inventory at either Amazon.ca or Amazon.com.
All orders are processed within 1 business day.
Your order will be marked as fulfilled from the moment it’s been boxed up in the warehouse awaiting for the courier to pick it up. Once your order has been fulfilled, you will receive an email with your tracking number. Your tracking details will appear once the courier has processed the package. CLICK HERE for more information about our shipping policy.

Legal Disclaimer
At Cronk Nutrients, we are committed to providing high-quality liquid plant fertilizers suitable for a variety of horticultural applications. Our products are designed for legal and responsible use by home growers and gardening enthusiasts. We do not condone or promote the use of our products for illegal purposes.
Customers are responsible for adhering to their local and state laws regarding plant cultivation. It is the sole responsibility of the customer to ensure compliance with all applicable laws and regulations. Cronk Nutrients will not be liable for any misuse of our products in violation of any laws.
By purchasing our products, the customer acknowledges their obligation to comply with the legal standards set forth in their jurisdiction and agrees to use our products in accordance with these laws. Cronk Nutrients reserves the right to refuse service to anyone suspected of using our products for illegal cultivation.
Thank you for choosing Cronk Nutrients for your plant nutrition needs. Grow with confidence, grow legally.