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North Blue Nutrients / Calcium System Support

Dual Cal Blend Fast + Sustained Calcium Support

A specialty powder blend combining gypsum and calcium lignosulfonate to support calcium availability, soil structure, and healthy root-zone function.

North Blue Nutrients Dual Cal Blend product package

Two Calcium Pathways

Dual Cal Blend is a specialty powder formulation designed to provide two complementary calcium sources for cannabis and other container-grown plants: calcium sulfate (gypsum) and calcium lignosulfonate.

Gypsum supplies calcium and sulfur without the strong pH-raising effect associated with liming materials. Calcium lignosulfonate provides calcium associated with organic lignosulfonate compounds, intended to complement the gypsum portion in a soil-focused nutrient program.

This dual-source approach is designed for growers seeking calcium support alongside soil structure, water movement, and root-zone nutrient availability. Always consider existing soil amendments, water quality, and nutrient inputs before adding supplemental calcium.

Use conservatively and adjust based on plant response and soil testing whenever available. Excess calcium can contribute to nutrient imbalance, especially in small containers or heavily amended media.

Component Benefits

Calcium Sulfate / Gypsum

Calcium + Sulfur

Gypsum is a mineral source of calcium and sulfur, two important plant nutrients that support healthy growth and development.

Calcium Sulfate / Gypsum

Soil Physical Support

In appropriate soils, gypsum can support aggregation, water infiltration, and management of compacted or sodium-affected growing media.

Calcium Lignosulfonate

Organic-Associated Calcium

Lignosulfonate-based calcium is included as a complementary source intended to support calcium availability in the root zone.

Calcium Lignosulfonate

Gradual Release Profile

The organic component is intended to break down more gradually than gypsum, contributing to a sustained calcium-support strategy.

Root-Zone Management

Nutrient Balance

Calcium is part of a balanced nutrient program. Monitor total inputs to help avoid antagonism with magnesium, potassium, and other nutrients.

Application Strategy

Measured Use

Use at planting, incorporate during soil preparation, or apply as a light top-dress and water in thoroughly.

Application Guide

For best results, incorporate into the soil before planting whenever possible. If top-dressing established plants, apply evenly around the root zone and water in well.

General Soil Use

Per Square Foot

  • Use approximately 1–2 tablespoons per square foot.
  • Work into the top layer of soil when practical.
  • Use at any growth stage as needed.
  • Base repeated applications on plant response and soil testing.
1-Gallon Pot / Soil Mixing

At Planting

  • Blend 1/2 to 1 teaspoon into potting mix.
  • Mix thoroughly before filling the container.
  • Use during soil preparation or at transplant.
  • Water normally after planting.
1-Gallon Pot / Top-Dress

Established Plants

  • Sprinkle 1/2 to 1 teaspoon around the soil surface.
  • Keep the powder away from direct contact with the stem.
  • Gently water the application into the top layer.
  • Reapply only as needed, generally every 4–6 weeks.

Use Responsibly

Avoid over-application. Excess calcium can contribute to nutrient imbalances, particularly in small containers, heavily amended soil, or feeding programs that already include calcium-rich water or fertilizer inputs.

For repeat use, assess plant response and use a soil test when possible. Soil texture, pH, water quality, existing nutrient levels, and cultivar needs all affect whether additional calcium is appropriate.