# pH Up

> pH Up is any alkaline additive used to raise solution pH, commonly potassium hydroxide or potassium carbonate; it is caustic and needs gloves and eye protection.

- Canonical: https://genetixbay.com/knowledge/glossary/ph-up.html
- Also written: pH increaser, pH plus, pH+, alkaline adjuster, pH up solution
- Glossary category: pH, EC and water · 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"

pH Up is the generic name for alkaline products that raise the [pH](https://genetixbay.com/knowledge/glossary/ph.md) of a nutrient solution or water. The usual active ingredients are potassium hydroxide (KOH, strong and fast), potassium carbonate (K₂CO₃) or potassium bicarbonate (KHCO₃), which also add a little buffering. All of them add some potassium.

## In practice

Most growers need pH Up less often than [pH Down](https://genetixbay.com/knowledge/glossary/ph-down.md), because [tap water](https://genetixbay.com/knowledge/glossary/tap-water.md) and many fertiliser mixes tend to be alkaline or drift upwards. It is most common with [RO water](https://genetixbay.com/knowledge/glossary/ro-water.md) and acidic nutrient blends, or in [coco](https://genetixbay.com/knowledge/glossary/coco-coir.md) and hydro when a new mix lands below about 5.5.

Add small amounts, stir or circulate for several minutes, and re-measure; RO water has little buffering, so a few drops can overshoot. Adjust after adding nutrients, never before. Dilute concentrated pH Up in water first for small reservoirs.

**Safety:** strong bases cause serious chemical burns to skin and eyes, often without immediate pain. Wear gloves and eye protection, store away from acids and out of reach of children and pets, and never mix pH Up and pH Down directly.

## Don't confuse with

- **Buffer additives**: carbonate-based products raise both pH and [alkalinity](https://genetixbay.com/knowledge/glossary/alkalinity.md).
- **Cal-Mag**: raises calcium and magnesium; it does not reliably raise pH.

## Related terms

[pH Down](https://genetixbay.com/knowledge/glossary/ph-down.md), [pH](https://genetixbay.com/knowledge/glossary/ph.md), [pH drift](https://genetixbay.com/knowledge/glossary/ph-drift.md), [Alkalinity](https://genetixbay.com/knowledge/glossary/alkalinity.md)

## Read more

- [pH drift in hydro: why reservoir pH rises (and sometimes falls)](https://genetixbay.com/knowledge/ph-ec/ph-drift-hydro.md)

## Sources

1. Bugbee B. 2004. Nutrient management in recirculating hydroponic culture. Acta Horticulturae 648:99-112. https://www.ishs.org/ishs-article/648_12