Add to cart
Bluelab Truncheon
  • Description
The best selling hydroponics EC Meter in the world. Growers prefer the Bluelab Truncheon because it's easy to use, easy to read, extremely accurate and best of all it's reliable.

Use it to quickly and accurately test the conductivity levels (EC, CF & PPM) of your nutrient solution.


  • EC, CF and PPM scales
  • Fully waterproof
  • Factory calibrated
  • Auto turn on and off
  • Battery life minimum of one year (or shelf life of battery)
  • No external switches or adjustment knobs
  • EC (0.2 - 3.6), CF (2 - 36) and ppm scales (TDS and 700 scale)
  • Uses 3 x AA alkaline batteries (included)

Testing is simple;

Dip the end of the Truncheon into the nutrient solution and wait for a minute or two for the Truncheon's probe to reach the same temperature as the nutrient.

  • Remove the Truncheon from the solution, and then dip back in again to take the reading.
  • The flashing lights along the side represent the value of the solution.
  • It doesn't get any easier.
  • Don't forget to rinse under fresh water after use, and clean once a week.

Handy Hint:  95% of all Truncheons returned to Holland Forge as 'Faulty' only require cleaning or new batteries. It's a great idea to buy a Cleaning Kit which contains everything you need, and check out the Cleaning Guide to keep your Truncheon in tip top condition.

Guardian Monitor

9421024 920081
Add to cart
Bluelab Guardian Monitor
  • Description
  • More Details

The Bluelab Guardian Monitor constantly measures conductivity, pH and temperature levels, and displays it in an easy to read LED.

Many factors determine how fast plants take up nutrients; season, stage of growth, temperature, and available light, just to mention a few. And with these variables the critical elements of the hydroponic nutrient can readily change. The Bluelab Guardian monitor makes the task of balancing these changes easier.

Main Features:

  • Adjustable display brightness
  • Three large easy to read displays
  • Green 'Plant Safe' LED display
  • Selectable values for conductivity and temperature
  • Simple push button pH calibration
  • No calibration required for conductivity and temperature
  • Silent alarm
  • All settings are retained if the power is lost
  • Automatic temperature compensation
  • Mains power supply
  • Water resistant design
  • Bluelab 2 year guarantee (6 months on pH probe) 

The 'Plant Safe' green LED' constantly displays the three critical nutrient parameters;

  • conductivity (EC, CF, TDS or PPM)
  • pH
  • temperature

This allows you to take a quick look at the monitor, and immediately see the precise levels of the nutrient solution.

The Bluelab Guardian monitor has a handy silent alarm function which can bring to your attention a possible problem. Simply set the optimum range you'd like your nutrient solution to be within. You can set temperature, pH and conductivity into the Guardian. Should the levels stray outside these ranges the unit's display will begin flashing alerting you to a possible problem.

The unit is mains powered so you don't need to mess around with batteries. It can be mounted in a convenient position close to your system, and the probes can be easily positioned in the nutrient reservoir with the suction holders.






0.0 - 14.0 


 2 Point


 0.0 - 5.0


 No Calibration Required


 0 - 50


 No Calibration Required


 0 - 2500


 No Calibration Required


 0 - 3500


 No Calibration Required


 0 - 50°C



Combo Meter

Add to cart
Bluelab Combo Meter
  • Description
The Bluelab Combo Meter is a portable all-in-one nutrient, pH, and temperature meter which can be used anytime and anywhere.

To take a reading - the two probes just need to be dropped into the nutrient solution, press the required mode (pH, EC, temp), wait a minute or two for the probes to adjust to the same temperature as the nutrient solution. View the readout. It's that simple.

Remember to rinse between testing different solutions, and rinse after use. The probes should be cleaned regularly to maintain accuracy, and ensure long life of the combo meter.

  • Selectable values for conductivity and temperature
  • pH range 0 - 14 pH
  • simple pH calibration
  • auto turn off
  • supplied with calibration solution
  • low battery indicator
  • batteries included
  • light weight & portable
  • 5 year warranty (6 months on pH probe)

pH Probe

Add to cart
Bluelab pH Probe Kit
  • Description
Replacement probe for Guardian Monitor and Combo Meter
  • Easy to clean
  • Fully waterproof to 10 metres
  • Gel filled (non-refillable)
  • Maintenance free

EC Probe Cleaning Kit

Add to cart
Bluelab Cleaning Kit
  • Description

Probe cleaning is one of the most important parts of owning and operating any Bluelab meter. If the probe is contaminated or dirty, it affects the accuracy of the reading displayed.

The probe surface is where the instrument takes the reading of the solution. The information is sent back from the probe to the electronic brain of the instrument. A calculation is then done in the instruments brain or micro computer and a reading is then displayed. If the information sent back from the probe is inaccurate due to probe surface contamination then the reading will be inaccurate.

Cleaning the probes is a very easy task and prolongs the life of the probes.

Especially recommended for use on Truncheons, Combo Meter and Guardian Monitor.

Keep your probe clean - it only takes a couple of minutes - and she'll love you for it.

The Bluelab EC Cleaning Kit contains;

  • Instructions
  • 2 x 20ml single use Conductivity standard solution sachets
  • Plastic Cup
  • Probe cleaner
  • Cleaning Tool

For cleaning the following;

  • Bluelab EC Truncheon
  • Bluelab Combo Meter
  • Bluelab Guardian Monitor


  Bluelab Cleaning Kit Instructions (pdf)