Extremely easy and no mess. The Kelway professional direct pH soil tester is used by thousands of nurseries across the world. It operates on the principle of electrical potential between two dissimilar metal plates. No batteries required. When inserted into moist soil, the HB-2 registers degree of acidity on the upper scale.
Litmus paper is difficult to use and interpret.
The Kelway Professional pH tester is portable, rugged, convenient, operates without a power source and is not overly sensitive to temperature variances. Great for individual pots or for entire beds.