Description
Fast, reliable nutrient readings without calibration
The Bluelab CF Truncheon Nutrient Meter provides a quick and dependable way to measure the strength of hydroponic nutrient solutions. Simply place the probe into your reservoir and the bright blue LEDs display the reading—without buttons, menus or complicated settings.
Fully waterproof and built for everyday grow-room use, the Truncheon measures EC, CF, PPM 500 and PPM 700. Its long 40.7cm design also allows you to stir and measure your nutrient solution using the same tool.
- Fully waterproof
- No calibration required
- Four measurement scales
- 5-year limited warranty
Why measure nutrient conductivity?
Conductivity indicates the concentration of dissolved nutrient salts within your water. Monitoring it helps you determine whether your plants are receiving the correct nutrient strength throughout each stage of growth.
A reading that is too low may indicate insufficient nutrition, while an excessively high reading can contribute to overfeeding, nutrient burn or dehydration. Regular testing removes the guesswork from feeding and helps prevent unnecessary nutrient waste.
How to use the Bluelab CF Truncheon
- Make sure the protective probe shroud is correctly fitted.
- Place the probe head into the nutrient solution.
- Stir gently and allow approximately 10 seconds for the reading to stabilise.
- Read the measurement indicated by the flashing blue LEDs.
If the LEDs alternate between two values, the correct reading is halfway between them. For example, alternating 0.8 and 1.0 EC indicates a reading of 0.9 EC.
Key features
- Measures EC, CF, PPM 500 (TDS) and PPM 700
- Fully waterproof construction for dependable reservoir testing
- Factory calibrated with no routine calibration required
- Automatic liquid detection and automatic on/off operation
- Bright blue LEDs remain readable in daylight
- Long-format design allows simultaneous stirring and measuring
- No buttons, switches, menus or adjustment knobs
- Robust construction designed for frequent grow-room use
- Easy-to-clean conductivity probe
- Powered by three AA alkaline batteries
- Meter length: 40.7cm
- Bluelab 5-year limited warranty with proof of purchase
Technical specifications
| Scale | Measurement range | Resolution | Accuracy at 25°C |
|---|---|---|---|
| EC | 0.2–3.6 EC | 0.1 EC | ±0.1 EC |
| CF | 2–36 CF | 1 CF | ±1 CF |
| PPM 500 (TDS) | 100–1800 PPM | 50 PPM | ±50 PPM |
| PPM 700 | 140–2520 PPM | 70 PPM | ±70 PPM |
Operating solution temperature: 0–50°C
Power: Three AA alkaline batteries
Warranty: Five-year limited warranty
Complete your nutrient management setup
Conductivity tells you the strength of your nutrient solution, but it does not measure pH. Pair the Truncheon with the Bluelab pH Pen to monitor pH and temperature alongside EC, CF and PPM.
Regular cleaning helps maintain accurate readings. The Bluelab EC Probe Care Kit contains the essential equipment needed to clean and test your conductivity probe.
You can also explore our complete range of pH and EC pens and meters .
Frequently asked questions
Does the Bluelab CF Truncheon require calibration?
No. The Truncheon is factory calibrated and designed to provide accurate conductivity readings without routine calibration.
What does the Bluelab Truncheon measure?
It measures nutrient-solution conductivity using EC, CF, PPM 500 (TDS) and PPM 700 scales.
Does the Bluelab Truncheon measure pH?
No. It measures nutrient conductivity only. A separate pH meter, such as the Bluelab pH Pen, is required to measure pH.
Is the Bluelab Truncheon waterproof?
Yes. The complete meter is waterproof and suitable for direct use in hydroponic nutrient reservoirs.
How quickly does it provide a reading?
Under normal conditions, allow approximately 10 seconds for the meter to reach the solution temperature and display a stable reading.
How should the probe be cleaned?
Rinse the probe with clean water after use. Clean the probe and removable shroud regularly using a suitable conductivity probe cleaner to prevent nutrient deposits from affecting readings.