The top 5 digital soil pH testers

The top 5 digital soil pH testers

If you’re into healthy, vibrant or fruitful plants it all begins with the soil. For successful home gardeners and horticulturalists, there is a powerful relationship between vigorous, thriving plants and soil pH. This article examines why measuring soil pH is so important. We also showcase the 5 best pH testers available in Australia and New Zealand at the present moment.

Soil pH and why it matters

Soil pH meters or ‘testers’ are simple-to-use devices that measure the acidity or alkalinity of a soil. They work by determining the hydrogen ion activity in the soil. The result is expressed as a ‘pH’ value. The pH scale is a logarithmic scale that ranges from 0 to 14. 0 is extremely acidic, 7 is neutral and 14 means completely alkaline.

Soil pH is important for plant growth as it affects the uptake of key nutrients. This means when the soil pH is outside the range required by your plants they will not grow to their full potential.


Figure 1 The relationship between pH levels and key nutrient uptake.

While each species of plant has its own ‘ideal’ pH range, most plants prefer a soil pH range of between 5.5 to 7.5. (See below examples of ideal soil pH levels for popular ornamentals plants, vegetables and fruits).

Digital soil pH testers are useful because they provide a quick, accurate and easy way to determine and interpret pH results. (To learn more on how to sample soil and keep your soil pH tester and electrode in the best shape, see our article, “How to use a soil pH meter”).

The five best digital soil pH testers

We asked Instrument Choice scientists to assemble a list of 5 digital soil pH testers they judged to represent the best, value-for-money, high performance devices available now. Here’s what they came up with….


1. Soil pH Meter with Separate Electrode
Product Code: PH220S

This accurate soil pH meter boasts an extremely fast sampling rate. Results are displayed on a digital screen. The PH220S is designed with a separate spear tip electrode that’s capable of penetrating moist and softer soils. 

the%205%20best%20digital%20soil%20pH%20testers%20pic%203%20.jpg?Action=thumbnail&algorithm=fill_proportional&2. HI99121, Direct Soil pH Measurement Kit 

With a user-friendly, multi-level LCD display the HI99121 is a versatile meter that is supplied with a specialised electrode for soft and moist soils and an auger to perforate firm or harder ground. Our scientists’ comments, “A great all-rounder”.

the%205%20best%20digital%20soil%20pH%20testers%20pic%204%20.jpg?Action=thumbnail&algorithm=fill_proportional&3. pHSpear - Spear Tip Waterproof pH Tester 

This tester is tough, waterproof and its all-in-one design (the sensor is contained in the conical tip) means you can measure the pH of soils with just one hand!

the%205%20best%20digital%20soil%20pH%20testers%20pic%205%20.jpg?Action=thumbnail&algorithm=fill_proportional&4. Soil pH Meter Kit 

With a large and easy-to-read LCD screen and high-powered soil pH electrode, this model has an impressive sampling time of 0.4 seconds! Ideal for applications requiring a large number of measurements.the%205%20best%20digital%20soil%20pH%20testers%20pic%206%20.jpg?Action=thumbnail&algorithm=fill_proportional&

5. GroLine Soil pH Tester 

This pocket-sized tester has an LCD screen that provides at-a-glance readings from any angle. The verdict? The IC-HI981030 is “best in class” if you need to measure the pH of soils on the go.

Examples of the ideal pH range for popular flowers and edible plants

The tables below provide a quick reference to the pH ranges that suit some of the more commonly grown plants. Becoming familiar with the ideal pH range for the plants you want to grow, and ensuring your soil stays within these limits will help you reduce the risk of crop failure, produce better specimens and reduce costs (e.g. reduce pesticides and fertilizers).

Ornamentals Ideal Soil pH Range 
Carnation 6.0-7.0
Chrysanthemum 6.0-7.5
Daffodil 6.0-6.5
Geranium 6.0-8.0
Hyacinth 6.5-7.5
Peony 6.0-7.5
Rose, rugosa 6.0-7.0
Sunflower 6.0-7.5
Tulip 6.0-7.0
Vegetables  Ideal Soil pH Range 
Asparagus 6.0-8.0
Broccoli 6.0-7.0
Carrot 5.5-7.0
Cauliflower 5.5-7.5
Cucumber 5.5-7.0
Garlic 5.5-8.0
Potato 4.8-6.5
Pumpkin 5.5-7.5
Tomato 5.5-7.5
Fruit Ideal Soil pH Range 
Apple 5.0-6.5
Blueberry 4.0-6.0
Cranberry 4.5-6.0
Orange 6.0-7.5
Melon 7.0-8.0
Peach 6.0-7.0
Pear 6.0-7.5
Plum 6.0-8.0
Raspberry 5.5-7.0



Digital soil pH testers are accurate, reliable and easy-to-use instruments. Our scientists recommend you keep one handy if you want the confidence of knowing that your soil’s pH is in the range to give your plants every opportunity to thrive.

While we have offered our five favourite pH testers for soil you might want to see more. Browse our full range of digital soil pH testers on the Instrument Choice website.

Need a bit of help finding the best digital pH tester for your needs? Not sure how to find the ideal soil pH for the plants you wish to grow? We’re here to help. Call us on 1300 737 871 or email [email protected].

Also interesting

The Top 4 Turbidity Meters in Australia

Turbidity meters are a water quality assessment tool that measures the turbidity (or cloudiness) of water. Turbidity meters are often used in water treatment plants, as well as in fieldwork to measure the water quality of rivers, lakes and mangroves.

For anyone interested in what makes one turbidity meter better than another, or overwhelmed by the range of turbidity meters on the market, Instrument Choice scientists have compiled a list of the top four turbidity meters currently available in Australia.

Read More
The Top 4 Turbidity Meters in Australia

The Top 3 Wireless Fridge Loggers

Monitoring and keeping fridges and freezes at a stable temperature is a critical factor in many environments, from food production facilities to pharmaceutical refrigeration.

Instrument Choice Scientists have selected the top 3 Wireless Fridge Loggers to help you find the best device for your application.

Read More
The Top 3 Wireless Fridge Loggers