Getting started: The Bluelab Truncheon Nutrient Meter

Product overview and how to take your first reading

Bluelab Truncheon Meter with callouts


The Bluelab Truncheon Nutrient Meter and Commercial Truncheon Meter are robust and reliable everyday tools for measuring nutrient concentration in solution. With the Truncheon, you’ll ensure that your plants are getting the nutrients they need for superior plant health. 

Our Truncheon is factory calibrated with no moving parts or switches. Simply submerge the probe in your nutrient reservoir and take the reading shown by the LED display. 


Blue light display No calibration needed
EC, CF and ppm 500 and ppm 700 scales Fully waterproof
5-year warranty (with proof of purchase) Auto off/on function

Register your product with Bluelab 

Product manuals:

TRUNV2 User Manual - English

TRUNV2 User Manual - German Deutsch

TRUNV2 User Manual - Spanish

TRUNV2 User Manual - Dutch

TRUNV2 User Manual - Canadian French

How to take your first reading 

To take your first reading, follow these steps. 

1. Remove the Truncheon from the packaging and ensure the shroud is fitted. (The shroud must be present as readings taken without it will be inaccurate.) 

2. Submerge the probe head into your solution.  

3. Wait 10 seconds or so for the thermistor to come to solution temperature.  

Note: For cold or warm temperatures, it may take 1-2 minutes for the probe to reach solution temperature. Try placing the probe in an area where there is strong movement of solution, or stir the solution with the probe.  

4. Read the measurement displayed by the blinking LEDs. If the flashing lights are alternating between two numbers, the measurement is the value between those two numbers. For example, if the lights are alternating from 0.8EC and 1.0EC, the reading is 0.9EC. 

For the Truncheon Commercial, if the measurement is between two points the lights will blink more frequently closest to the measurement. 

Tip: Besides being used to measure nutrient levels, the Truncheon Meter can also be used to mix your nutrients into your solution. 

5. The Truncheon will turn itself off after around 10 seconds. If further measurements need to be taken, take the Truncheon out of the solution, wait a few seconds, and place it back in. It will turn on again. 

6. We recommend the probe be cleaned and accuracy verified in Bluelab 2.77 EC Solution once every month. 

Further reading 

How to clean your Bluelab Truncheon 

How to change the Bluelab Truncheon battery

FAQ and troubleshooting for the Bluelab Truncheon 


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