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How to Calibrate Blue Lab pH Pen

Water quality is crucial for your plant’s wellbeing. Bluelab’s PH pen is an awesome tool, giving you key information so your grow can have the highest quality water it can have. They are waterproof and fully submersible and useful in any situation in regards to testing your water or reservoir.

When you purchase one of these pens here at herbal house, we offer to ship you a pre-calibrated pen, however if you follow along with this guide we can show you how to calibrate it and care for it, so that you can make this piece of equipment last.

Bluelab pH pen unboxing 

So starting with the Bluelab PH pen, you get a beautiful box with the PH pen inside. And three coloured sachets. Now, the red and yellow stripped sachets are there for calibrating initially out of the box.

As soon as you get the pen and some storage solution in a blue stripped sachet which will be topping up in the base of the cap. That's going to help look after the probe.

How to calibrate your pH pen

To calibrate the PH pen first you have to open the PH seven and PH four sachets, we highly suggest to either store this in small cups or to leave it in the sachets just so you can dip the pen in.

Bluelab pH pen instructions

Firstly we start by turning on the pen by pressing the power button, we then take the cap off and dip it into the PH seven solution first and we leave it there for around 30 seconds. Once the pen has settled it should read 7 on the display, once you see it read the correct number, you keep the pen in the solution while you hold the CAL button which stands for calibrate and wait for it to fully calibrate as a loading bar will appear. So on the display it should say CAL and seven at the bottom. Now, if you run into any problems it will say ER for error. If this does happen, consult the troubleshooting guide.

Once that is completed, dip the probe into a cup of tap water and stir, this is to get rid of the excess so we do not cross contaminate, making the calibration inaccurate. Then shake some of the water off but DO NOT dry the probe, if you do the pen is ruined.

Bluelab ph pen calibration

When then repeat the same process in the PH four solution, waiting 30 seconds for the number 4 to appear on the display, we then hit CAL and leave it to do its thing. Then once again lightly rinse the probe and place it back in its cap. It is CRUCIAL that the probe stays moist otherwise the pen will die.

From this point on there should be a little tick in the corner of the display, that means it is calibrated and will give you accurate results. This tick will last around 30 days however if in that time you have only used it once or twice, there is no worry to calibrate again, although it is a good benchmark for keeping the pen as accurate as possible.

Care and maintenance 

Overtime your PH pen will gather a scaly film on top of its sensor which could throw off your readings, to avoid this we can gently rinse glass dome at the end of the pen or if you have the PH probe care kit, use the small soft brush and apply the pH probe cleaner to the end of it and scrub very gently, rinse and apply the KCI storage solution on the inside sponge in the cap to make sure the probe stays moist as just remember, If it dries, It dies.

When given the proper care these pens are indispensable in maintaining and caring for your grow, so we want yours to last as long as possible. If you have any questions, feel free to contact us at matt@herbals.co.nz.