With the instructions, you can scan them and keep a pdf on your computer and/or keep in a plastic pocket and put in filing cabinet with other instructions or in your kitchen with recipe books or a draw.
With any pH reagent test kit, you would pour a small amount of water into the clear bottle provided, then add 1 or 2 drops of pH Reagent into it and mix gently. The water will change colour. Now match the water colour to the corresponding colour on the pH colour chart. This will give you the pH of your water. Easy… If you're in Australia, can you purchase this kit from here: www.alpswaterfilters.com.au/product/water-ph-test-kit/