Swimming pool owners of the 21st century have their choice of filters to keep pool water clean. The most common swimming pool filters are the ones containing sand as their filtering material. Sand swimming pool filters are also characterized by their low maintenance. Typically, you only have to change pool filter sand every seven years or so. Also, there are specific types of sand used in swimming pool filters, with pool filter sand being of a finer grade than sandbox sand, for instance.
- According to Pool Center.com, a pool filter’s sand is #20 silica sand and only .45 to .55 mm in size. The sand in pool filters has also been specially graded so it’s able to trap particulate matter 20 to 100 microns in size. Pool filter sand is actually a crystalline silicate and not like the sand found on a beach. Because pool filter sand is crystalline silicate–based, it’s also not really suitable for use in sandboxes, for instance
- The sand in a child’s sandbox, in comparison to the sand in a swimming pool filter, is less refined and more like beach or river sand. However, play sand can come from a number of sources, including crushed rock or silica-type sand. Pool filter sand is very small and formulated especially for water filtration, whereas crushed silicate or rock sand is less refined. There are many companies now selling specifically formulated play sand for use in sandboxes and not pool filters.
- Pool filter sand is specifically made the way it is and with silica because it needs to effectively trap particles in a swimming pool’s water. Silica is also used as pool filter sand because of the way it attracts particulate matter in water passing through it. As water passes over filter sand, particles suspended in the water adhere to the edges of the sand. As pool filter sand keeps filtering water, more and more particulate matter ends up trapped.
- Don’t use any sand in your swimming pool filter that’s not formulated and sized specifically for use in a pool filter. Beach or river sand meant for sandboxes and the like is of a different composition than silica-based pool filter sand and won’t filter water as efficiently. You can sharpen and refresh pool filter sand through use of a commercial filter cleanser. Backwash, or reverse, your pool filter every week to ensure that the sand inside it stays as clean as possible.