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Bluelab CF Pen

From £64.95
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Bluelab CF Pen Code: 2034
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Don’t overfeed or underfeed plants! Monitor your nutrient strength & temperature with a Bluelab CF pen.

It doesn’t cost much, but it’s just what you need.

You can hold readings and choose your units. To make life easy, calibration is optional.

Since temperate affects CF, your CF pen has automatic temperature compensation. That way, you get an accurate reading every time.

It also takes your nutrient temperature, so you can keep it inside the ideal range (18 - 21oC).

Use it every time you change or top up your feed. 

• Measures CF/EC and nutrient temperature
• Automatic temperature compensation
• Choose your units: °C, °F, EC, CF, ppm 500 and ppm 700

Backlit LCD display
Optional calibration
• Successful calibration indicator
Hold reading function
Low battery warning
• Fully waterproof
Auto off function (after 4 minutes)
• Smart loop handle
1 year warranty included

We recommnd teaming this CF pen with a Bluelab pH Pen to cover all bases.



Nutrient strength is measured in EC (electrical conductivity) or CF (conductivity factor).

Both units tell you how many dissolved salts are in your solution. The difference is, 1 EC is equivalent to 10 CF. In the same way 1cm = 10mm.

The EC/CF to aim for depends on how hard your water is and what stage of growth you’re at. As a rough guideline, aim for:

• Young plants = 6 – 12 CF (0.6 - 1.2 EC)
• Establishing plants = 10 – 16 CF (1.0 - 1.6 EC)
• Mature plants = 15 – 20 CF (1.5 - 2.0 EC)

If your feed isn’t strong enough, you could underfeed plants. If it’s too high, plants can dehydrate (not enough water).






Make sure you clean the probe every two weeks to prevent build ups. You also need to rinse the probe under running water after each use. Doing this ensures your reading is always accurate.

To operate,

• Turn on and off by holding the power button
• To measure EC & temperature, place the probe in the solution and wait
• Press the hold button to hold a reading, the power button to exit
• To change units, hold the unit button, then short press it to scroll through options.


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