... to use Portable Safe Drinking water tester: Features:Color: YellowPower: 110~220V.ACAdvantage: 1. Easy to operate 2. High precision 3. Convenient to ... water electrolysisYellow: dissolved acids, fluoride, and other organic matterGreen: arsenic, mercury, lead, copper, sodiumBlue: bacteria, viruses, carcinogens, chemical fertilizers, pesticides, etc.Red: Iron ...