Four tips for accurate measurements with your soil pH tester

Maintaining the right soil pH is important if you want to grow healthy happy plants. Why? Because soil pH has an impact on a plants ability uptake of key nutrients from the soil. Soil pH is easily obtained from a pH tester, but how can you ensure your pH tester is giving you accurate measurements?

About Soil pH

The pH scale is a measure of acidity or alkalinity of a substance. It is a logarithmic scale ranging from 0 to 14, with 0 being extremely acidic, 7 being neutral and 14 being alkaline. When your soil’s pH is outside your plants’ ‘ideal’ range nutrient uptake is suboptimal, which means your plants will not grow to their full potential.

Soil pH can be impacted by a wide range environmental factors and can fluctuate often. Some common influences include fertilizer, soil type, weather, irrigation, nutrient availability, as well as other plants in the area.

So, to if want healthy, luscious plants how do know that your soil’s pH is within the range that your plants prefer? While it’s simple to obtain soil pH readings using a pH meter, how do you know your device is producing accurate results? In this article Instrument Choice scientists share the four things you must do if you want accurate results from your pH tester.

Four tips for accurate soil pH measurements

#1: Calibration

Regular recalibration of your soil pH tester is a must. It’s easy task done using buffer pH solutionsand can be done in a matter of minutes. The calibration frequency and method will depend on the device you use, as well as how precise your readings need to be and how often your meter gets used. First refer to the instructions supplied with your pH meter tester or contact us if you’re not sure what calibration regime is right for you.

It’s recommended you always calibrate your pH meter to a minimum of two points, shouldering your expected pH range. However, the more calibration points your unit has, the greater the accuracy of your device post calibration. The most common buffer solutions used for pH calibration are pH 4.01, 7.00 and 10.00.

#2: Electrode Storage

One of the key design components of a soil pH tester is a glass ‘pH bulb’ filled with a hydrated gel layer. To obtain accurate readings this layer must remain constantly hydrated. This means when your soil pH tester is not in use, it must be properly stored using Electrode Storage Solution to stop the electrode drying out.

IMPORTANT: Never store your pH electrode in water (potable, deionised or distilled). This will shorten the lifespan of the pH electrode. If you don’t have any storage solution on hand, you can substitute pH 4 buffer solution, but only in the short term. If you have mistakenly allowed your electrode bulb to dry out, rehydrate it in storage solution for 3-4 hours and re-calibrate before use.

#3: Electrode Cleaning

It’s important to keep your it clean to keep your soil pH electrode in prime condition and extend its life. Never wipe down your electrode with a tissue or towel, instead rinse it with deionised water. For more stubborn soil soak the electrode in cleaning solution and then rinse down with deionised water.

#4: Regularly Replace Your Tester’s Electrode

Electrodes are a consumable item. Depending on your usage a soil pH electrode should be replaced every 6-24 months. Here are three ways you can tell if it’s time to do so. Look out for:

• Unstable or slow readings
• Difficulty calibrating the pH meter correctly
• Physical signs of damage or wear and tear.

While calibrating, cleaning and correctly storing your electrode probe will help extend the operational life of your electrode, when any of the above signs appear it is time for a replacement.

Conclusion

Soil pH testers are instruments that make testing soil pH easy. However, to ensure accurate soil pH results from your tester you must correctly store, as well as regularly clean, calibrate and replace your tester’s electrode.

If you have followed our scientist’s tips and are still getting unstable readings, or if you need a hand with calibration – give us a call, we are here to help! Contact an Instrument Choice scientist on 1300 737 871 or email [email protected]