The Searles Soil pH Test Kit method is based on research from CSIRO and does not require calibration when purchased as this is done within a laboratory setting when the kits are manufactured. This home test kit is designed to be used on soil only as the liquid in the kit reacts with soil allowing a pH indication when the powder is applied. As with all chemical products it is to be stored in a cool, dry place out of bright light. Chemicals can break down over time and old test kits can give false reading, so if your kit is more than a year old we recommend replacing it with a new one to provide a more accurate result.
The soil sample for testing should not be obtained from the surface of the pot or the garden. The best sample to test is located 5-10cm below the surface, in the well mixed areas.
The test sample should be no more than one teaspoon full in size. Be careful not to have manure or fertiliser present in the sample, as this may have a large impact on readings and skew the results. Place the sample onto the clean test plate. Remnants of past tests must not be present as this will give an incorrect reading.
Using a small amount of pH indicator liquid into the sample, mix into a thick paste. Avoid making the mix too runny as this can cause a false reading to occur.
When mixed with the liquid to form a thick paste, lightly dust the top of sample with the indicator powder. Adding too much powder can lead to a false reading. A light dusting is all that is required.
Wait 30 seconds to two minutes and then compare the colour of the sample to the chart provided under natural light.
This is a home test kit and not a precise laboratory test. The perception of the reading can vary by up to 1.0 as people perceive colours slightly differently, plus colour variances from blending and the organic/manure composition of test sample can also affect the results shown. For a more accurate test we recommend contacting a soil analysis laboratory to arrange a test of your soil.