Sand Filters

Sand filters are the workhorse for the pool industry. They are arguably  the most common filter installed in the Raleigh area and are essential for most public or commercial applications that have a high bather load.  

Cartridge and DE filters can be fantastic for some residential applications; however, a high bather load (lots of swimmers) or a large amount of minerals and/or debris in the water can quickly clog these filters.  The filter cartridge or element must then be disassembled and cleaned.

Sand filters can easily be cleaned through backwashing.  This is typically done using a multi-port valve to change the directional flow of water in the filter, lifting the sand and pumping the dirt, oil and debris to a waste source.   

Typically the sand in filters needs to be changed every 5 years.

When it’s time to change your sand:
 

1.  Remove the old sand from the swimming pool filter.  To do this you will need to pull the drain plug and let the water drain out, ideally for an entire day. Wet sand is much heavier than dry sand!

2.  Use a small cup to dig out the sand so you can expose the laterals and move the stand pipe out of the way.

3.  Use caution when digging the sand out so you don’t break the laterals (pictured below).  They are fragile and are easily broken.

4.  Once the sand is completely removed, clean and  examine the laterals. Most laterals will unscrew allowing for easy removal from the tank.

5.  If you need to remove impacted dirt from the laterals, soak them in a mix of water and muriatic acid then rinse thoroughly.

6.  Rinse out the tank and re-install the clean laterals.

7.  Replace the drain plug then add water until the tank is half full to cushion the laterals when you start to add the sand.

8.  Add a bag of sand, making certain you level the sand in the sand bed before you add the next bag of sand. The amount of sand you need to add is determined by the manufacturer’s instructions.

9.  Once the proper amount of sand has been added, reassemble the filter tank and multiport valve.

10.  It’s important to start your filter system in the backwash mode to completely flush the dust from the sand and to allow the sand to settle completely around the laterals.

Because cleaning a sand filter is not something that is done with any regularity, you may find it easier to contact a swimming pool professional when the time comes to replace the sand in your filter.