My pool serviceman comes twice a week and checks the chemical levels. Do I still need to do that?

YES! The law requires all public pools and spas to have an on-site operable test kit, and a daily log of chlorine, pH levels, and other maintenance actions. You should have basic knowledge of pool maintenance and water chemistry balance. If the pool chemistry is not correct on any given day, adjustment must be made as soon as possible to keep the water safe for patrons.