Water Analysis

Water quality testing is one of the important steps in pool maintenance. The amount of disinfectant used, water hardness and pH changes, all of these must be checked and adjusted regularly. Here are the different parameters to be monitored, the different tools to be used, not to mention the procedures for testing pool water according to the rules of the art.

Different parameters to be analysed

Water is a chemical substance composed of H2O molecules. This compound is very stable but also very reactive, to ensure healthy and clean water for the bathers, and to guarantee a long life to the equipment, it is important to proceed regularly to the analysis of the water of your pool.

Water analysis includes the quality control and balance of the pool water, which involves the examination of different parameters that can be tested one by one, or sometimes simultaneously. Water is balanced between 3 parameters: pH, alkalinity and hardness. To better understand them, read our article « Three parameters that have an impact on water balance. »

In what order should we check the parameters ?

When testing your pool water, it is best to start with hardness and alkalinity, as these have a direct influence on the pH of the water. Once adjusted, there is a good chance that the pH of the water will change.

Water testing procedure

Sampling; take 1 cup of water 30 cm below the water line.
Test with tools such as test strips, liquid reagents and tablets, and electronic testers.

·       Analysis with strips :
·       Dip a strip into the water horizontally for one second.
·      Take the strip out and wait 15 seconds. Compare the colours        obtained with those shown on the bottle. You will be able to tell if        the chemicals are balanced or need adjusting.

·       Specimen analysis :
·       Fill the two test tubes with water and pour off the excess.
·       Add the required number of drops to each test tube. Put five drops of OTO         in the test tube for chlorine and five drops of Phenol in the test tube for the         pH test.
·       Put in the stopper and shake the whole device.
·       Compare the colors obtained with those shown on each side of the kit.
Interpret your results once the analysis is complete.

Table showing the parameters and optimum values for the pool water

Parameters to check	Optimum value	Ajustment to increase	Ajustment to reduce
Alkalinity	Between 80 and 120 mg/L	Addition of baking soda	Water circulation
Water hardness	Between 10 and 25° F	Addition of magnesium or calcium product	Diffusion of a lime sequestering agent
pH	Between 7,2 and 7,4	Addition of pH + product	Addition of a pH - product
Disinfectant rate	Bromine: between 1,2 and 3 mg/L Chlorine: between 1,5 and 2 mg/L Salt: between 3 and 7 g/L	Addition of disinfectant product	Bromine: add a neutralizer Chlorine: add sodium thiosulfate Salt: draining part of the water
Stabilizer rate	Between 20 and 30 mg/L	Addition of stabilizing product	Partial draining of the pool

Recommended frequency of analysis :

For alkalinity and hardness about 1 time / month during the swimming season.

For pH and disinfectant level about 1 time / week when the pool is in use.

For the stabilizer level, 2 times / year.

In order to ensure your well-being and that of those around you, Club Piscine Super Fitness offers you the possibility of coming to analyze your pool or spa water for FREE. Our water treatment specialists will give you the right information on the quality of your water and will give you tips and advice, if necessary.

Check out our Water Testing section to see which products will be useful when testing water at home.