Sand filters use a special grade of silica sand to help filter the small particles from your pool’s water. When working properly, it will filter particles down to about 30 microns. If you looked at the sand under a microscope, you’d see it has sharp edges. Over time two things can happen to these “sharp edges”.
The first is erosion of the sand itself. Just as water rushing over rocks in a river will cause them to round off over time, the sand in your filter does the same thing. The sharp edges disappear, and the sand is only able to trap larger particles. This means a cloudy pool. And because algae spores will also pass through, a green pool can happen if your sanitizer level drops too low.
The second thing that happens to the sharp edges of the sand, is an accumulation of oils from the swimmers in the pool (i.e., suntan lotions, hair gels, etc). Sand can be chemically cleaned, but it is usually easiest and best to change it every 4-5 years. If you have a powerful shop vac, it’s a fairly straightforward process, and we have instructions to help you out. But done improperly, damage to the centre tube / lateral assembly can occur.
If you don’t want to take chances, give us a call!