# Macronutrient

> A macronutrient is an essential element plants need in large amounts, measured in tens to hundreds of mg/L: nitrogen, phosphorus and potassium, plus calcium, magnesium and sulfur.

- Canonical: https://genetixbay.com/knowledge/glossary/macronutrient.html
- Also written: macronutrients, macro nutrients, macros, primary nutrients, major nutrients
- Glossary category: Nutrients · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Macronutrients are the essential mineral elements a plant needs in the largest quantities, typically present in dry leaf tissue at 0.1% to several percent. The primary macronutrients are nitrogen (N), phosphorus (P) and potassium (K). Calcium (Ca), magnesium (Mg) and [sulfur](https://genetixbay.com/knowledge/glossary/sulfur.md) (S) are also macronutrients, often called [secondary nutrients](https://genetixbay.com/knowledge/glossary/secondary-nutrient.md). Carbon, hydrogen and oxygen come from air and water and are not counted as fertiliser nutrients.

## In practice

A typical cannabis hydro feed carries macronutrients in the tens to hundreds of mg/L (ppm): roughly 150-200 N, 30-60 P, 150-300 K, 120-200 Ca, 40-70 Mg and 50-100 S, varying with stage and system. [Fertiliser labels](https://genetixbay.com/knowledge/glossary/guaranteed-analysis.md) highlight [N-P-K](https://genetixbay.com/knowledge/glossary/npk-ratio.md), but Ca, Mg and S shortages cause just as many problems, especially with [RO water](https://genetixbay.com/knowledge/glossary/ro-water.md) and [coco](https://genetixbay.com/knowledge/glossary/coco-coir.md).

## Don't confuse with

- **Micronutrient**: needed in far smaller amounts, but just as essential.
- **Macros in diet slang**: protein, fat and carbohydrate, unrelated.
- **Importance**: "macro" refers to quantity, not to how essential an element is.

## Related terms

[Micronutrient](https://genetixbay.com/knowledge/glossary/micronutrient.md), [Secondary nutrient](https://genetixbay.com/knowledge/glossary/secondary-nutrient.md), [N-P-K ratio](https://genetixbay.com/knowledge/glossary/npk-ratio.md), [Nitrogen](https://genetixbay.com/knowledge/glossary/nitrogen.md), [Potassium](https://genetixbay.com/knowledge/glossary/potassium.md)

## Read more

- [Building a cannabis feed by stage: ppm targets per element and how to hit them](https://genetixbay.com/knowledge/nutrients/feed-by-stage.md)

## Sources

1. Marschner P (ed.). 2012. Marschner's Mineral Nutrition of Higher Plants, 3rd ed. Academic Press. https://doi.org/10.1016/C2009-0-63043-9