• Green Planet Nutrients Horti Cal - 50 LBS
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Product benefits

  • All-Stage Support
  • Calcium & Magnesium Support
  • Fully Water Soluble
  • Clean Formula
  • Dripper Friendly
  • Multi-Media Ready
  • Multi-System Use
  • Clean Sediment-Free Formula

This product may offer additional benefits beyond those listed.

Frequently purchased together

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Green Planet Nutrients Horti Cal - 50 LBS

Vegetative Stage Flowering Stage Indoor Outdoor Regular Watering Watering Systems Hydroponics Coco Coir Safe Soil Soilless

OTHER AVAILABLE SIZES / MODELS:

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Manufacturer Recommended Products

These manufacturer-recommended products are designed to be used with this product for proper performance and best results. In multi-component systems, all recommended components should be used together as directed to help ensure effective use.

Product benefits

  • All-Stage Support
  • Calcium & Magnesium Support
  • Fully Water Soluble
  • Clean Formula
  • Dripper Friendly
  • Multi-Media Ready
  • Multi-System Use
  • Clean Sediment-Free Formula

This product may offer additional benefits beyond those listed.

Description
Description
GreenPlanet Nutrients Horti Cal is a water-soluble dry fertilizer built to support plant strength across the entire growth cycle. This soluble calcium and magnesium fertilizer is designed to reinforce core nutrition in demanding gardens, with a clean, commercial-style formula that fits both vegetative stage and flowering stage programs.

Horti Cal is formulated to supplement nitrogen, calcium, and magnesium, helping maintain healthy plants while encouraging rapid growth and development. A compact facts layer: it’s rated 14-0-0 and is identified as “+ Ca + Mg,” making it easy to place as a focused support product when your garden needs more calcium and magnesium alongside nitrogen. It’s positioned to keep plants strong from start to finish, giving you a simple way to back up key elements without changing the intent of your base nutrition plan.

As part of the Horti line, this formula is built from water-soluble ingredients and is described as highly soluble and consistent in each batch. It’s also described as pH stable, which supports a steadier nutrient solution profile in production-minded setups. The Horti line is stated to contain no fillers or contaminants, with zero sediment or organic material to block irrigation systems, keeping the focus on clean delivery and dependable handling in modern grow rooms and greenhouses.

Horti Cal is a good fit for growers who want a dry fertilizer that supports strong plants, steady growth and development, and clean system performance. It’s especially well suited to facilities that value batch consistency, water-soluble ingredients, and a pH stable formula. If you run stock tanks and injection systems and want a calcium and magnesium fertilizer designed to support the entire growth cycle, GreenPlanet Nutrients Horti Cal matches that goal with a straightforward, commercial-grade profile.
How to use
Vegetative stage - Horti Cal:
- Week 1: mix 0.66 g per litre of water or nutrient solution.
- Week 2: mix 0.66 g per litre of water or nutrient solution.
- Week 3: mix 0.66 g per litre of water or nutrient solution.

Flowering stage - Horti Cal:
- Week 1: mix 0.66 g per litre of water or nutrient solution.
- Week 2: mix 0.66 g per litre of water or nutrient solution.
- Week 3: mix 0.66 g per litre of water or nutrient solution.
- Week 4: mix 0.66 g per litre of water or nutrient solution.
- Week 5: mix 0.66 g per litre of water or nutrient solution.
- Week 6: do not use this product during this week of flowering.
- Week 7: do not use this product during this week of flowering.
- Week 8: do not use this product during this week of flowering.
Product benefits
Vegetative Stage; Flowering Stage; Indoor; Outdoor; Regular Watering; Watering Systems; Hydroponics; Coco Coir Safe; Soil; Soilless; All-Stage Support; Calcium & Magnesium Support; Fully Water Soluble; Clean Formula; Dripper Friendly; Multi-Media Ready; Multi-System Use; Clean Sediment-Free Formula.
Guaranteed analysis
Total Nitrogen (N): 14.0%; Ammoniacal Nitrogen (N): 0.9%; Nitrate Nitrogen (N): 13.1%; Calcium (Ca): 14.8%; Water Soluble Magnesium (Mg): 2.0%.
Derived from
Ammonium Calcium Nitrate Double Salt; Magnesium Nitrate.

How To Use

How to Use Green Planet Nutrients Horti Cal - 50 LBS

Step-by-step mixing and feeding instructions for Green Planet Nutrients Horti Cal - 50 LBS.

Mixing & preparation

Fill your reservoir or watering container with clean, room-temperature water first. Shake the bottle of Green Planet Nutrients Horti Cal - 50 LBS well before every use. Using the feeding schedule below, measure the recommended dose and add it directly to the water while stirring. Allow the solution to mix fully before adding any other fertilizers, additives, or supplements.

Always add nutrients to water — not the other way around. Mix thoroughly between products to ensure an even, stable nutrient solution.

Week-by-week feeding schedule

Vegetative stage — Horti Cal

  • Week 1: mix 0.66 g per litre of water or nutrient solution.
  • Week 2: mix 0.66 g per litre of water or nutrient solution.
  • Week 3: mix 0.66 g per litre of water or nutrient solution.

Flowering stage — Horti Cal

  • Week 1: mix 0.66 g per litre of water or nutrient solution.
  • Week 2: mix 0.66 g per litre of water or nutrient solution.
  • Week 3: mix 0.66 g per litre of water or nutrient solution.
  • Week 4: mix 0.66 g per litre of water or nutrient solution.
  • Week 5: mix 0.66 g per litre of water or nutrient solution.
  • Week 6: do not use this product during this week of flowering.
  • Week 7: do not use this product during this week of flowering.
  • Week 8: do not use this product during this week of flowering.
Tips for best results
  • Maintain pH and EC/ppm within the range recommended for your growing medium and crop.
  • Use fresh nutrient solution whenever possible and avoid leaving mixed solution stagnant for long periods.
  • Store nutrients in a cool, dark place away from direct sunlight and extreme temperatures.
  • Keep bottles tightly sealed when not in use to reduce air exposure and preserve product quality.
  • Use clean measuring tools and regularly rinse or clean your reservoir, lines, and irrigation equipment.
Common mistakes to avoid
  • Do not mix different nutrients or additives together in concentrated form before adding them to water.
  • Do not exceed the recommended dosage unless you are following a tested, crop-specific feeding plan.
  • Do not skip pH or EC/ppm checks when growing in hydroponic or soilless systems.
  • Do not allow the nutrient solution to freeze or overheat, as this can damage the formulation.
  • Do not ignore the directions on the product label for your specific crop, growth stage, and system type.

Warnings & Safety
Important – Safety Information

This product may cause mild skin irritation and eye irritation. Avoid unnecessary contact with skin, eyes, and clothing. Use only as directed.

General Safety Precautions

Read and follow all instructions on the product label and any accompanying documentation before use. Keep out of reach of children and pets. Do not ingest. Avoid breathing vapours, mist, or dust that may be generated during handling or use.

Wear appropriate personal protective equipment (PPE), such as protective gloves, long sleeves, long pants and closed-toe footwear. When there is a risk of splashing or airborne particles, use safety glasses or other suitable eye and face protection.

First Aid – Skin Contact

IF ON SKIN OR HAIR: Remove contaminated clothing immediately. Rinse skin with clean water for several minutes, then wash with mild soap and water. If irritation or redness develops and persists, seek medical attention. Wash contaminated clothing before reuse.

First Aid – Eye Contact

IF IN EYES: Rinse cautiously with clean water for several minutes, keeping eyelids open. Remove contact lenses if present and easy to do. Continue rinsing. If irritation persists, obtain medical advice.

First Aid – Ingestion

IF SWALLOWED: Rinse mouth thoroughly with water. Do not induce vomiting unless instructed by a medical professional. Seek medical attention if you feel unwell.

First aid – Inhalation

IF INHALED: Move the person to fresh air and keep them comfortable for breathing. If coughing, breathing difficulty, dizziness or other symptoms occur, seek medical assistance.

Storage And Handling

Store this product in its original closed container, in a cool, dry and well-ventilated area. Protect from extreme temperatures and direct sunlight. Keep container tightly sealed when not in use.

Avoid release to drains, natural waterways or outdoor soil. Dispose of unused product and empty containers in accordance with local regulations and the directions on the label.

Important – Medical

If medical advice is needed, keep the product label or container available. Always follow the specific instructions and safety recommendations provided by the manufacturer. This safety notice is intended as general guidance and does not replace official label directions or documentation.

Guaranteed Minimum Analysis
Total Nitrogen (N) 14.0%
Ammoniacal Nitrogen (N) 0.9%
Nitrate Nitrogen (N) 13.1%
Calcium (Ca) 14.8%
Water Soluble Magnesium (Mg) 2.0%

Derived From
Ammonium Calcium Nitrate Double Salt
Magnesium Nitrate

Frequently Asked Questions
Why is total nitrogen (N) important for plant growth, and what makes it different from other nutrients?

Total Nitrogen is important because it directly drives leafy growth, chlorophyll production, and overall growth speed, which sets the pace for the entire plant. It’s unique because the “total” number can include different nitrogen forms that behave differently in the root zone, meaning the same total amount can produce very different results depending on the nitrogen type and plant stage.

Read the full guide

What Is ammoniacal nitrogen (N) and why do plants need It?

Ammoniacal Nitrogen (N) is a plant-available form of ammonium (NH₄⁺) that provides a steady, gentle source of nitrogen for healthy green growth. Unlike fast-release nitrogen types, ammoniacal nitrogen feeds plants slowly, helps stabilize root-zone pH, and works well in cooler temperatures. It is commonly used during early vegetative growth because it supports strong leaf development without burning young roots. If plants show pale leaves, slow growth, or weak stems, they may need more available ammoniacal nitrogen.

Read the full guide

What does nitrate nitrogen (N) do for plants?

Nitrate Nitrogen provides a stable, easy-to-absorb form of nitrogen that supports steady growth, strong foliage, and reliable plant development without sudden nutrient swings.

Read the full guide

Why is calcium important for plant growth?

Calcium is important because it builds and stabilizes plant cells as they form, acting as the structural support that keeps new growth strong and functional. Unlike other nutrients that drive color or speed of growth, calcium’s role is unique because it controls cell wall strength and membrane stability, making it essential for healthy roots, shoots, and long-term plant resilience rather than quick visual results.

Read the full guide

Why is water soluble magnesium important for plant growth?

Water soluble magnesium is important because it quickly restores the plant’s ability to make chlorophyll and produce energy, which helps stop interveinal yellowing on older leaves and improves overall nutrient use; it’s unique because it becomes available immediately in water, making it faster and more predictable than slower magnesium sources.

Read the full guide

Why do growers use ammonium calcium nitrate double salt instead of a single-form nitrogen source?

Growers use ammonium calcium nitrate double salt because it can provide nitrogen in a balanced way while also supplying calcium to support stronger new growth. It’s important because it can boost growth without pushing plants as harshly as nitrogen sources that are only ammonium or only nitrate, and it’s unique because the built-in calcium helps keep fast growth from turning into weak, easily stressed tissue.

Read the full guide

What does magnesium nitrate do for plants?

Magnesium nitrate supplies fast-available magnesium for chlorophyll and photosynthesis while also adding nitrate nitrogen that can speed up greening and growth. It’s unique because it can correct magnesium-related yellowing quickly but also changes growth momentum, so it’s most valuable when magnesium is truly limiting and the plant can safely use extra nitrate.

Read the full guide

Frequently purchased together

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Nutrient Feed Chart

Vegetative — Week 1

  1. Horti Cal
    —
  2. Horti Grow
    —
  3. Horti Bloom
    —
  4. Horti Late Bloom
    —
  5. Horti Late Cal
    —

Flowering — Week 1

  1. Horti Cal
    —
  2. Horti Grow
    —
  3. Horti Bloom
    —
  4. Horti Late Bloom
    —
  5. Horti Late Cal
    —

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