You are here: Indoor Swimming Pool Guide » Pool maintenance » Complementary Water Testing Methods

Complementary Water Testing Methods

You can find below complementary water testing methods : Total Dissolved Solids (TDS) , Cyanuric Acid Testing, Copper Testing, Iron Testing, Test Strips for Water Chemistry Levels.

Total Dissolved Solids (TDS)

Total dissolved solids (TDS) is the measurement of all materials dissolved in the water, i.e. calcium, dissolved organic and inorganic materials, carbonates, salts from chlorine residue, swimmer waste, soluble hair and body lotion, or anything placed in the pool that can be dissolved. The total dissolved solids (TDS) in a pool should not exceed 1,500 ppm. High TDS is common with spa water with high bather load, high chemical needs and a relatively small volume of water. TDS can only be corrected by dilution with water with low TDS or completely draining and refilling with fresh water. Determining the TDS level requires a special meter or test kit. Testing meters normally have a scale with a range of 0-5,000 ppm. TDS kits are priced according to quality and accuracy.

Cyanuric Acid Testing

Cyanuric acid is commonly added to outdoor pools as a chlorine stabilizer or chlorine conditioner. The concentration of cyanuric acid must be monitored carefully to insure that the chlorine does not become over stabilized. Cyanuric acid products are not recommended for indoor pools and spas, since the need for chlorine protection from the sun is not a concern.

The acceptable range of cyanuric acid is generally between 30-80 ppm. Cyanuric acid levels above 100 ppm are prohibited by the MDEQ. Most cyanuric acid tests are conducted by mixing stabilized melamine solutions and pool water, which results in a cloudy solution. Astir or dip rod, with a black dot on the rod, is placed in the viewing test cell. The rod is lowered into the solution. A graduated scale is used to measure when the black dot disappears from view. Other test methods include tablets or more concentrated reagents. All tests are based on turbidity (cloudiness) of the solution. Melamine tests are not very accurate below 15 ppm or above 70 ppm.

Copper Testing

Test kits are available to detect copper in pool water. Most copper test kits produce a blue or green color when copper is present in the pool water. The copper level (ppm) is measured by the color standard included with the test kit. Copper found in pool water contributes to staining of pool walls, water discoloration, and turns hair or nail cuticles of the pool users green or blue. Therefore, the recommended copper level is 0 ppm. If copper is present, maintaining a pH of 7.2 to 7.3 and a hardness of 350 ppm reduces the negative influences of copper.

Iron Testing

Test kits are available for testing iron concentration levels. Reagents produce brown to red colors in the presence of iron. The reddish brown color is then measured with a color standard found in the test kit. Dissolved iron is responsible for staining and color problems in pool water and on pool surfaces. The addition of chlorine in an adequate concentration helps to precipitate out the iron and allows the filter to remove it.

Test Strips for Water Chemistry Levels

Test strips are available to determine chlorine and pH values as well as all other parameters of water chemistry. These test strips are easy to use but they are only useful as general guidelines. Do not rely upon test strips for accurate water chemistry readings. Record Keeping When performing your water tests, keep a written record of the results. This information is helpful for understanding the dynamics of your pool’s system. Over time, you may notice trends and be able to anticipate water needs and keep a tighter control on your water quality. This information is also useful for making purchasing decisions. The MDEQ requires that certain information be maintained.