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. The 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. The PRO250 PLUS outfit includes all of the above plus Copper and Iron tests.