# CF

> CF (conductivity factor) is an EC scale used mainly in Australia, New Zealand and the UK, where 1 CF equals 0.1 mS/cm (100 µS/cm).

- Canonical: https://genetixbay.com/knowledge/glossary/cf.html
- Also written: conductivity factor, CF units, CF reading, CF scale
- 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"

CF (conductivity factor) is a unit of [electrical conductivity](https://genetixbay.com/knowledge/glossary/ec.md) common in Australian, New Zealand and some UK hydroponic literature and meters. It is EC scaled by ten to avoid decimals: 1 CF = 0.1 [mS/cm](https://genetixbay.com/knowledge/glossary/ms-cm.md) = 100 [µS/cm](https://genetixbay.com/knowledge/glossary/us-cm.md). So a solution of 1.6 mS/cm is CF 16.

## In practice

CF is a straight multiplication, with no conversion-factor ambiguity, unlike ppm. If a nutrient chart from Australia says "CF 12–16 in veg", that is EC 1.2–1.6 mS/cm. Some older Australian charts quote even higher flower values (CF 20–25); treat those as upper limits, since controlled cannabis trials do not show yield gains from pushing nutrient concentration hard.

When sharing numbers on GenetixBay, use mS/cm so everyone reads the same scale.

## Units and formula

- CF = EC (mS/cm) × 10
- EC (mS/cm) = CF ÷ 10
- CF 10 ≈ 500 ppm ([500 scale](https://genetixbay.com/knowledge/glossary/ppm500.md)) ≈ 700 ppm ([700 scale](https://genetixbay.com/knowledge/glossary/ppm700.md))

## Don't confuse with

- **Conversion factor**: the multiplier that turns EC into ppm (0.5 or 0.7); despite similar words, it is a different thing from CF.
- **ppm**: a calculated estimate that depends on meter scale.

## Related terms

[EC](https://genetixbay.com/knowledge/glossary/ec.md), [mS/cm](https://genetixbay.com/knowledge/glossary/ms-cm.md), [ppm500](https://genetixbay.com/knowledge/glossary/ppm500.md), [ppm700](https://genetixbay.com/knowledge/glossary/ppm700.md)

## Read more

- [EC vs PPM: the 500 and 700 scales, CF, and how to convert](https://genetixbay.com/knowledge/ph-ec/ec-ppm-scales.md)

## Sources

1. University of California Cooperative Extension, Ventura County. Salinity units and conversions (640 ppm = 1 dS/m). https://ucanr.edu/node/125832