No, it isn't really necessary if you can be aware of the symptoms of unblanced skin.
A good rule of thumb is that harsh soaps will increase the alkalinity (dry, flaky, sallow, wrinkles start). Too acidic, red, irritated, blemished and oily/shiny.
Tonik balances most skin types, Turbo oilier. Once you have the balance and you are aware of the skin type (oily, normal, dry) you can recommend products.