Pool clarifiers

Cloudy or milky water is often caused by the presence of fine suspended particles, which the filter alone cannot capture. According to our guide to visual problems for swimming pools, the recommended solution is to use a clarifier. This product works by grouping these microscopic impurities together so that they can be more easily captured by the filtration system. Within a few hours, the water will regain its clarity and crystal-clear appearance.

Generally, a clarifier takes between 12 and 24 hours to make water clearer, provided the filtration system is running continuously and the filter is clean. If the water was very cloudy or contained a high concentration of fine particles, it can take up to 48 hours. Thoroughly brushing the walls and cleaning the filter will also speed up the process.

To clarify the water, start by checking the pH (7.2–7.6) and ensure the filtration system is working properly. Then add a clarifier, which clumps together fine particles so they can be trapped by the filter. Let the filter run continuously until the water is clear again. In more severe cases, a flocculant can be used to make the particles settle, but this requires vacuuming the system.

The clarifier acts like a magnet for suspended particles. It clumps together small impurities that are too fine for the filter to trap, forming larger particles that the filter can then capture. The clarifier therefore directly improves the filtration process and accelerates water clarity.

Clarifier is used when the water becomes cloudy, after a shock treatment, after a heavy storm, or when the filter has difficulty capturing fine particles. It can also be used as a preventative measure each week to keep the water clearer, especially during periods of heavy swimming.

The best clarifier depends on the type of filter:

•Sand or glass filtersLiquid or cartridge clarifiers are very effective for clearing cloudy water.

•Cartridge filters: mild liquid clarifiers or models specifically designed not to clog the cartridge.