One of the fundamental components in the filter used in pool cleaning is sand. The filter and pump together are responsible for approximately 80% of the water treatment in a swimming pool.

The filter sand retains impurities from the water that passes through it. Of course, in order for the filter to continue showing efficiency, it is necessary to carry out maintenance on the equipment periodically.

See when you should change the pool filter sand!

Problems with pool filter sand

While the water filtration is going on, the pool filter sand it goes through wear, it undergoes polishing and the grains get smaller. Finally, the sand hardens and becomes dirty. Compacted, it loses its properties to carry out a good quality filtration.

In swimming pool water, there are generally high concentrations of magnesium and calcium ions, which cling to the sand and form blocks (silicates). Passing through the filter, the pool water encounters silicates on its way. As it cannot pass through them, it bypasses them and does not undergo filtration.

One way to avoid this problem is to control the quality of the pool filter sand, checking for silicate blocks and maintaining the correct pH levels.

Filter maintenance basically consists of 2 operations: cleaning and backwashing. If this maintenance (backwash) is not done regularly, the chances of the sand having problems will increase. Clean at least once a week when the pool is always used. In winter, do it once a month. In water with a lot of limestone, annual chemical cleaning is recommended, ie descaling the sand.

The right time to change the pool filter sand

In general, it is recommended to change the pool filter sand after 3 to 5 years of water usage. If the water does not have much limestone and the filter is always well maintained, this period can be extended to 7 years.

The frequent change of sand, without it presenting any problem, should be avoided.

Consideration should be given to replacing material at the end of 2 or 3 years to keep the filter sand at the appropriate level. For this operation, sand with identical granulometry must be used, that is, the dimensions of the grains must be equal.

Tests to see if it's time to change the sand in the pool filter

There are a few simple tests a person can do to make sure it's time for a switch.

First, check if the flow in the injectors is weaker after washing the filter. If there is, look at the clear filter hood and see if limescale deposits appear. If you confirm the presence of these deposits, it is a surefire sign that you need to change the pool filter sand.

You can also see if the pool water, despite being chemically balanced and periodically filtered, is not in good condition.

Another thing that can be done is to open the filter and dip your hand into the sand. If the sand flows between your toes, it's a sign that it doesn't need to be changed yet. If the sand has hard blocks, it is a sign that it needs to be changed.

If you notice that the sand is disappearing from inside the filter and you see signs of it in the water, you will need to remove all the sand to fix the equipment. This is a problem in the collectors (crepins) and they are located at the bottom of the filter.

Have you performed these tests to make sure it's time to change the pool filter sand? How long does it take to change the sand? Does your pool water have a lot of limestone? Leave a comment in the spaces below and share your experiences!