Swimming Pool Sand Filters

If you have decided on a sand filter for your swimming pool filter you should first heed to the general rule of having the filter large enough to handle the job. Keep in mind it is better to have it and not need it, rather than need it and not have it. It is the same concept with swimming pool filters, even sand filters. Sand filters use specialized silica blend sand, generally in the 45 to 55 mm range.

The reason sand works well as a filter is that the sand has squared edges. The edges provide the surface t0 grab the contaminates in the water. The sand of course is very small, so it is able to collect contaminates in the 20 to 100 micron range.It is vital that the recommended amount of sand be used for the filter. This information should be available from the manufacture.

When you first start your sand filter you should pay particular attention to the pressure of the filter. In most cases the pressure should be at between 8 and 10 psi. In the future, if you notice an increase in this pressure it indicts the filter is having to work harder, this means you should pay attention. The answer could be as simple as back-washing the filter, or it could give you a early warning of a more serious problem.

It is generally said that most sand filters should change sand every 6 to 8 years. This of course will depend on the water and usage, pools that are shut down for long periods will very. The reason for the sand being changed is because the edges of the sand grains will be come rounded with time and not be as efficient at grabbing the contaminates. When the sand is replaced, the new sand will be able to grab the contaminates much better.

Back washing the filter is basically the routine use of water to clean the water. This process is done by using the multi valve on the filter to force water backwards through the filter. This dislodges the contaminates from the sand grains therefore rejuvenating the usefulness of the sand. The water is then discarded outside of the filter rather than in the pool.