A recent study calls into question the reliability of test kits for water quality testing.

Test kit results were found to have ?unacceptable differences? from more precise lab tests, some as much as 300 percent, according to Dr. Damian Kachlakev, director of the National Pool Industry Research Center at California Polytechnic State University in San Luis Obispo.

Manufacturers in the study were Taylor Technologies, AquaChek Pool & Spa Test Strips, Jack?s Magic Products, Palintest USA, LaMotte Co., and Pentair Water Pool and Spa.

The study used two identical water samples. Kits tested the first sample, while the second was tested in a lab using strict ASTM procedures.

Each test was assessed by a team of three people, including a manufacturer representative. Other team members were from the Independent Pool & Spa Service Association, National Plasterers Council, United Pool Association, and the Association of Pool & Spa Professionals.

NPIRC already has begun the second phase of the study, in which six universities around the nation will invite the same test-kit manufacturers to participate. Each university will test two water samples tap, or common, water and campus swimming pool water.

Those samples also will be tested in the lab using ASTM procedures, Kachlakev explained. A team consisting of the NPIRC associate director and representatives from IPSSA, UPA, NPC and APSP will travel to each college to act as witnesses, bringing with them the tap water sample and a test kit purchased directly from the manufacturers. Kachlakev said that the universities then would purchase a second kit from a local pool retailer.

How results will be revealed has not yet been determined. Manufacturers will not know the results of other companies? kits unless they agree to support the publication of the results, with the brand names provided, Kachlakev said.