5:1 Cal-Mag (Powder)
Fast-acting, finely ground calcium and magnesium amendment for rapid correction. Ideal for pots, raised beds, soil blending, and situations where a quicker response is needed.
A finely milled blend of dolomite and limestone formulated at a 5:1 calcium to magnesium ratio. Designed to address deficiencies while gently raising low soil pH, this product supports root development, nutrient uptake, and overall plant performance.
The fine particle size increases surface area, enabling faster soil reactivity and more immediate availability of calcium and magnesium. It also helps make nutrients already present in the soil more accessible, improving uptake efficiency and consistency.
In biologically active soils, calcium plays an important role in soil structure and microbial balance, while magnesium supports chlorophyll production and overall plant function. When used appropriately, this product helps create a more stable and productive root zone.
Why the 5:1 Ratio Matters in Living Soil
The 5:1 calcium-to-magnesium ratio was developed through years of hands-on soil building, testing, and consulting with growers working in raised bed and living soil systems. It reflects real-world use in biologically active soils that are re-amended and reused cycle after cycle.
In closed-loop systems, cation balance does not reset between crops. Calcium (Ca²⁺), magnesium (Mg²⁺), and potassium (K⁺) occupy exchange sites on soil colloids (CEC) while also cycling through the soil solution. With each crop, these nutrients are actively taken up and removed—especially in high-demand crops like cannabis.
Calcium and magnesium are continually drawn down through plant uptake and must be replenished to maintain both soil structure and plant function. In many living soil systems, this is managed through soluble inputs (such as liquid cal-mag) to maintain adequate levels in the soil solution.
At the same time, potassium tends to accumulate more readily if not carefully monitored. Over time, this can shift cation balance, competing with calcium and magnesium at both the root interface and exchange sites.
Maintaining a calcium-forward ratio helps stabilize this relationship. It supports:
- Consistent availability of calcium and magnesium in the root zone
- Balanced competition between Ca²⁺, Mg²⁺, and K⁺
- Stable soil structure and pore space
- Predictable nutrient uptake across successive cycles
The 5:1 ratio is designed to work alongside soluble feeding strategies, helping maintain proper base saturation and cation balance as soils are reused. Rather than reacting to imbalances after they appear, it provides a consistent framework for managing calcium, magnesium, and potassium over time.
This makes it particularly well-suited for:
- Living soil beds under continuous production
- Cannabis and other high-demand crops
- Systems using liquid inputs to manage the soil solution
- Growers actively monitoring and adjusting cation balance
Application
Garden Beds, Raised Beds & Lawns 🌱
Apply 400–600 g per 10 m² (1–1.5 lbs per 100 ft²). For maintenance, test soil and reapply seasonally as needed.
Pots, Containers & Soil Blends 🪴
Apply 5 mL per gallon of soil volume when a slight adjustment or added calcium and magnesium is needed. Mix thoroughly into the growing media.
Greenhouse & Commercial Growing 🌿
Suitable for soil blending or targeted correction in larger systems. Apply based on soil test results and crop requirements.
Always test your soil before applying. Because this is a fast-acting fine powder, it reacts quickly and is easier to over-apply than coarser materials.
In living soil systems, this product is best used to address clear deficiencies or imbalances rather than for frequent adjustment. Over-application can disrupt nutrient balance and soil biology.
We offer lab soil analysis and can help determine the correct application rate based on your specific conditions.
This product is best suited for soils that are low in calcium and trending acidic. Where magnesium levels are already sufficient, the 5:1 ratio provides a more balanced option than standard dolomite lime.
Typical Analysis
- Calcium (Ca): 30%
- Magnesium (Mg): 6%
This product complies with Canada’s Organic Production Systems General Principles & Management Standards and Permitted Substances Lists (CAN/CGSB-32.310-2021 CAN/CGSB-32.311-2020)
