# Manganese sulfate

> Manganese sulfate (MnSO4) is the common soluble manganese source for DIY micronutrient mixes, about 32% Mn in the monohydrate form.

- Canonical: https://genetixbay.com/knowledge/glossary/manganese-sulfate.html
- Also written: MnSO4, manganese sulphate, MnSO4·H2O, manganous sulfate
- 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"

Manganese sulfate is the salt of [manganese](https://genetixbay.com/knowledge/glossary/manganese.md) and [sulfate](https://genetixbay.com/knowledge/glossary/sulfate.md), usually sold as the monohydrate (MnSO4·H2O) at about 32% Mn. A tetrahydrate form also exists, with less Mn per gram (about 24.6%). It is soluble and pale pink.

## In practice

It is the usual Mn source in home-made micronutrient stocks, often alongside zinc sulfate, [copper sulfate](https://genetixbay.com/knowledge/glossary/copper-sulfate.md), boric acid and [sodium molybdate](https://genetixbay.com/knowledge/glossary/sodium-molybdate.md), with [chelated iron](https://genetixbay.com/knowledge/glossary/iron-chelate.md) added separately. The final solution typically needs only about 0.5-1 mg/L (ppm) Mn, so the salt is dosed in milligrams per litre, ideally from a concentrated stock rather than weighed fresh each time. In high-pH conditions, [chelated](https://genetixbay.com/knowledge/glossary/chelate.md) manganese is more reliable than the sulfate.

## Units and formula

1 mg of the monohydrate per litre gives about 0.32 mg/L (ppm) Mn. To reach 0.5 ppm Mn, add about 1.6 mg/L.

## Don't confuse with

- **Magnesium sulfate**: [Epsom salt](https://genetixbay.com/knowledge/glossary/magnesium-sulfate.md); Mg, not Mn.
- **Manganese chelate (Mn-EDTA)**: stays available at higher [pH](https://genetixbay.com/knowledge/glossary/ph.md).

## Related terms

[Manganese](https://genetixbay.com/knowledge/glossary/manganese.md), [Sulfate](https://genetixbay.com/knowledge/glossary/sulfate.md), [Micronutrient](https://genetixbay.com/knowledge/glossary/micronutrient.md), [Stock solution](https://genetixbay.com/knowledge/glossary/stock-solution.md)

## Read more

- [Manganese (Mn) in cannabis: netted chlorosis, low-pH toxicity and the iron balance](https://genetixbay.com/knowledge/nutrients/manganese.md)
- [Hydroponic salts explained: what each fertiliser salt supplies](https://genetixbay.com/knowledge/nutrients/hydroponic-salts.md)

## Sources

1. Sonneveld C, Voogt W. 2009. Plant Nutrition of Greenhouse Crops. Springer. https://doi.org/10.1007/978-90-481-2532-6