There are a variety of testing kits available for home or commercial use. Test strips - dip and read one strip that usually measures chlorine, pH and total alkalinity. A simple OTO/pH test kit- this is popular and inexpensive. OTO is used for testing chlorine residuals and phenol red is used for testing pH. A DPD test kit uses a tablet to test for free available chlorine plus phenol red for pH. 5 in 1 test kit - provides five tests - DPD#1 for free available chlorine, pH, total alkalinity, plus tests for acid and Alkali Demand. A professional model is recommended for commercial pools. Generally for small 12'x36" pools a simple OTO/pH test kit is adequate. For larger pools we recommend the 5 in l test kit. Test strip are also great to use! Above Ground Pools: Air Blowers: Cartridge Filters: Chlorine Generators: Filter Grids: Fountains: Pool Accessories: Pool Tables: Above Ground Pools: Solar Heating: Spas: Spa Pumps: Swimming Pool Alarms: Swimming Pool Controls: Swimming Pool Cleaners: Swimming Pool Filters : Above Ground Pools: Swimming Pool Heaters: Swimming Pool Lights: Swimming Pool Ladders: Swimming Pool Pumps: Swimming Pool Lights: Pool Features and Benefits: Policies: FAQ: Copyright © 1998 1 Swimming Pool Supply Inc.- Swimming Pools and accessories www.1swimmingpools.com We are proud suppliers of the finest Manufacturers in the industry. Our Manufacture of Swimming Pools, Above ground swimming pools, Above ground Swimming Pool Pumps,inground pool pumps, pool lights, above ground pool lights, solar panels, pool filters, de filters, cartridge filters, de grids, whisperflo, hayward super 2, Spa Pumps, above ground Pool Supplies, Spas, Hot Tubs, Hot Tub Supplies, and Spa Accessories include; Hayward Pool Parts, Pacfab, Splash a round, Aquaflo, Sta-Rite, Jacuzzi, Rainbow, Blue Devil, Whisperflo, American Products and Splash Around and are all registered trademarks of their respective companies. This website has no direct affiliation with any of the above named companies.