pH Meter – Measure your Soil’s Acidity

A pH Meter is a device used to measure the acidity of the soil, or in the case of hydroponics, a solution. Different plants like different levels of acidity and you can use your acidity meter to determine whether the soil has the right acidity or if you need to make it more acidic or alkaline.

A pH of 7 is called neutral (e.g. water). A pH less than 7 is called acidic and more than 7 is called basic or alkaline.

How to Measure the pH of Soil

Before measuring, make sure that your meter has been calibrated.

To measure the pH of your soil, take a sample of the soil using a trowel or small gardening spade. Make sure that the implement is clean. Mix this 1 part of soil to 5 parts of distilled water and let it stand for a couple of minutes.

Make sure your meter’s probe is clean and then insert it into the water and wait for the reading.

How to choose a good Meter?

These features are nice to have, but not necessary:

  • Accurate to one decimal place
  • Replaceable electrodes. The electrodes are what are most likely to wear out on an acidity meter
  • A waterproof housing
  • Automatic temperature compensation
  • An automatic-off feature to prevent the batteries being emptied if you forget to switch it off


Instead of buying a meter, you can also use pH indicator papers to measure the soil’s pH. This is a cheaper method.