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Rules for water chemical testing

The following rules apply to all chemical testing:

1. The law in your state will require that pool water be tested at least three times a day with the results recorded on a daily operational sheet. Test at times when the pool is used to capacity or during normal peak periods of use.

2. Make certain that the sample is representative of the pool water. Select a sample location that contains well-mixed pool water. Obtain your sample from at least 12” below the water’s surface. Do not collect the sample from an area adjacent to an inlet.

3. Follow test kit instructions—water testing is a precise process that demands accuracy in measuring amounts of reagents involved and in observing time and temperature requirements.

4. Add the water sample to the tube until the bottom of the curved-upper surface (called the meniscus) is even with the prescribed level. The outer edges will be higher than the center causing a curvature in the water surface. This curvature is called a meniscus.


Fill the sample tube with pool water so that the low point of the meniscus rests at the fill mark.

Have the fill line at eye level when filling the sample container.


5. Rinse all solution tubes, stirring rods, and equipment thoroughly after each use, both inside and outside. Do not rinse droppers or reagent bottles, or let the droppers touch pool water. Rinse the droppers only with a small amount of the reagent with which they are associated. Do not handle the equipment or reagents with dirty hands, and, never cover the sample tube with a thumb or a finger. Rinse off any reagents that get on the skin.

6. Properly box or case the equipment, and store in a cool, clean, dry place. Do not interchange parts such as solution tubes, bottle caps, or droppers.


Reckless or inexact methods of water testing leads to inaccurate results and possibly an unsafe condition for people using the facility. Water must be kept in a healthy, clean and clear condition at all times.