Bluelab Original Truncheon Nutrient Meter | EC 0.2-3.6, CF, ppm 500/700

Bluelab Original Truncheon Nutrient Meter, No Calibration Needed

The Truncheon is a one-piece conductivity wand that tells you how strong a nutrient solution is before it reaches the plants. A probe at the tip reads the solution and a column of blue LEDs on the stem lights at the matching value. It covers 0.2–3.6 EC at 0.1 resolution, with accuracy of ±0.1 EC at 77°F. The same stem also carries a 2–36 CF scale. Growers on ppm can read 100–1,800 ppm on the 500 scale or 140–2,520 ppm on the 700 scale. Temperature compensation is automatic, and the meter works in solutions from 32–122°F. There is no calibration routine, no on/off button and no screen to fog up. It switches itself on when it touches liquid and off again shortly after it comes out. Three AA alkaline batteries in the sealed cap power it. The body is fully waterproof, and Bluelab backs it with a 5-year warranty. That combination is why so many reservoirs have one leaning against the rim.

Reading Feed Strength with a Waterproof EC Meter

Hold the probe in the solution for a minute or two so it settles to the same temperature as the tank. Stirring the reservoir with the stem speeds that up and mixes the nutrients at the same time. Lift it out, dip it back in, and read the value where the lights flash. When the lights dance between two marks, the true reading sits halfway between them. Check the fresh mix, then check runoff, and the difference tells you whether salts are building in the media. The probe needs cleaning every two weeks with a plain, unscented cream cleanser and a chamois. Scented or abrasive cleaners damage the probe face and throw readings off. Use alkaline cells only, because rechargeable batteries are not suited to the meter. The scale tops out at the high end of a normal feed, so strong stock solutions and heavy late-flower feeds can run past its ceiling. It reads conductivity only, so pair it with a pH meter for a full picture of the tank.

Key Features

• No Calibration Required: The meter arrives ready and stays accurate without calibration solutions or adjustment screws.
• Four Scales on One Stem: EC, CF, ppm 500 and ppm 700 sit side by side, so it fits any feed chart.
• Blue LED Display: Bright lights read clearly in daylight or under grow lights, with nothing to fog or crack.
• Fully Waterproof Body: It can be dropped in a reservoir and used as a stirring rod without harm.
• Automatic Temperature Compensation: Readings adjust for solution temperature across the working range.
• Auto On and Off: Contact with liquid switches it on, and it turns off by itself after use.
• 5-Year Warranty: Bluelab backs the meter for five years against defects.

Technical Specifications