If you've had your Grobo for more than 1 year, we recommend changing your pH probe. Each probe contains a liquid inside that is necessary for it to measure pH. Over time, that liquid gets used up and the probe no longer gives accurate readings.
To complete this, you'll need:
1x pH Probe
Please follow the steps outlined in the PDF below to replace the probe.
Once you've replaced your probe, it's important to immediately calibrate the new probe.