Every PRO250 SERIES kit includes color-coded caps to prevent mixups, and diagrammed instructions make testing a breeze. The POOL MGR. Water Quality handbook and saturation index calculator are also included. These professional water analysis kits are supplied in durable, blow-molded cases for years of dependable service. Each unit features liquid reagent systems for chlorine and pH (capable of 280+ tests each). The liquid DPD reagent system is provided to monitor chlorine, while pH is tested with a single liquid indicator. Total Alkalinity, Calcium Hardness, Acid Demand and Base Demand are analyzed with drop count titrations. Cyanuric Acid is measured by turbidity.