Sooner or later, as with any hobby, you begin acquiring tools that make your favorite pastime more productive, in addition to enjoyable. Scuba divers may purchase a sophisticated dive watch, foodies could invest in premium culinary knives and an audiophile would be meticulous in his or her choice of an amplifier. Hydroponic gardening is no exception. Whatever your passion, it definitely helps to have the right tools at your disposal. For this review will be taking a close look at the Bluelab Truncheon Nutrient Meter with an eye for ease of use, quality and performance.
Bluelab’s nutrient truncheon:
Bluelab is New Zealand based company known primarily for their pH and conductivity meters, with the nutrient truncheon being one of their signature products. This handheld nutrient meter resembles a plastic wand that can be dipped into a nutrient solution for the purpose of measuring the water’s electrical conductivity. For hydroponic gardeners this measurement can provide important information. Pure water conducts electricity rather poorly and given the addition of hydroponic nutrients, water hardness and other dissolved solids, the electrical conductivity will measurably increase. Measuring this conductivity allows insight into the overall “saltines” of a solution in a reservoir and can be used to more effectively manage a hydroponic nutrient program.
Nutrient Truncheon with box.
Two varieties of the truncheon nutrient meter are currently available. First is a standard meter that measures between 0.2 -3.6 EC. In addition, there is also commercial model that measures within an expanded range of electrical conductivity; 0.4 – 6.0 EC. While both instruments function in the same manner the commercial truncheon is suited for those working with nutrient solutions that are applied at higher concentrations. The standard meter will suffice for a majority of our readers and that will be the focus of this review. Both cost roughly the same. Just be aware that two options exist and because they are nearly identical in appearance and in name, it’s possible to unknowingly purchase one while intending to buy the other.
Truncheon with accessories. Even batteries were branded Bluelab.
Technical details:
The nutrient truncheon measures a length of 41 cm (16 in) and has a diameter of 2 cm (0.8 cm) and retails for approximately $130 US. As stated previously, this is the standard model and the primary difference between it and the commercial variant is that this measures within a tighter range of conductivity. Included are three alkaline AA batteries, instruction booklet and some additional product literature. Since the plastic body of the truncheon is shrink wrapped and the battery cap sealed with a rubber o-ring, the truncheon is effectively waterproof. This means there is little reason to be concerned over accidentally dropping the entire truncheon into a reservoir. However, it’s worth knowing that the five-year guarantee does not include damage incurred as the result of water leaking into the truncheon due to a missing or damaged o-ring. Because of this, I would recommend periodically inspecting the o-ring, just to ensure it remains in working order. For many, this aforementioned five-year guarantee is one of the major drawing points of the nutrient truncheon. If that’s high on your list, just remember to save your store receipt in a safe place. It wouldn’t hurt to register the truncheon with Bluelab after removing it from the box either. While the printed warranty states the truncheon must be registered with Bluelab within 14 days of purchase to redeem this guarantee, a representative of Bluelab informed me that so long as you possess the original store receipt there shouldn’t be issue with redeeming the warranty. That’s good to know.
Features, usage and perspective:
Using the nutrient truncheon could hardly be easier. It comes factory calibrated and loaded with batteries, meaning it can be put immediately to work after removing from the box. In addition, the truncheon turns on and off automatically. This allows for one handed operation, simplifying tasks like opening containers or taking notes. The nutrient truncheon’s unconventional appearance may give the impression that it’s confusing to read. Thankfully, reading a measurement from the truncheon is quick and simple. Just identify the LED that’s illuminated and read the measured value. Units are displayed in electrical conductivity, conductivity factor, total dissolved solids of sodium chloride or total dissolved solids of potassium chloride. Don’t let these terms intimidate you. They are just various units of measure, similar to how a kilometer and mile are different. To Bluelab’s credit, the included instruction booklet provides a clear explanation to what all these terms mean. Something that wasn’t intuitive to me however was how the index scale on the truncheon appears to be upside down while in use (see picture below).This is a rather minor issue since it’s not difficult to read an inverted number, especially after some repeated use. I can’t help but think it would have been better to have the index appear upright from this perspective. Grizzman from the hydroponic forums on Gardenweb was quick to point out the following:
“Also, one note about your comment that the numbers are upside down. This is only true if you’re checking a solution at waist height. my reservoirs are placed on the ground. I have to (well not have to, but generally do) bend over to dip the stick into the liquid. Of course, this causes my head to invert which, in turn, makes the numbers appear upright.”
Using the truncheon. I don't drink from this bottle.
Several additional features that I appreciated; the truncheon’s wand shape allows it to double as a stirring rod for small and medium sized containers while mixing nutrients, the cloth loop on the battery cap allows for hanging on a wall hook and no routine calibration is necessary for the truncheon. Furthermore, the general shape and size of the nutrient truncheon make checking multiple reservoirs much easier and ergonomic than lowering a wired probe into a container. Maintaining the probe is also straight forward. Just remove the probe shroud and wipe down the probe head with some soap that is free of dye and perfume using your fingertip. While the LED indicators don’t allow for the more precise readings provided by traditional conductivity meters, something necessary for work done in a laboratory setting, most gardeners will likely agree that the several convenience factors mentioned previously outweigh this limitation.
Final Conclusion:
In summary, Bluelab’s nutrient truncheon is a unique conductivity meter that is both quick and simple to use. Not practical for work in a lab, the truncheon really shines when testing several reservoirs in quick succession. In addition, it works straight out of the box, requires no calibration and the five-year guarantee is superior to what you will find from competing manufacturers. If you are looking for a conductivity meter, definitely give Bluelab’s nutrient truncheon a closer look.
Pros: Simple, fast, fully waterproof, convenient to use and a five year guarantee.
Cons: Not practical for a laboratory. Reading the index