- 1). Rinse out the test tube supplied with the kit using some of the water to be tested, then fill the tube to the 5 mL mark with the sample water.
- 2). Add 10 drops from the kit reagent bottle to the sample, then swirl the tube to mix the reagent into the sample water.
- 3). Insert the reaction zone portion of a test strip into the water sample for one second.
- 4). Withdraw the strip and allow excess water to drain off, then wait precisely one minute.
- 5). Compare the color of the test strip reaction zone to the color chart provided with the test kit. Choose the color on the chart most closely matching the color on the strip, then read the associated formaldehyde concentration. The kit will provide a reading of formaldehyde concentration in units of milligrams per liter, which is identical to parts per million, or "ppm."
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