Understanding your Sand Filter – Part 1

Does your pool equipment make you feel over-whelmed, and anxiety ridden?  Your pool filter is an important part of your pool circulation system and if it is not working properly you can end up with a pool that is inviting an algae bloom.  If you don’t understand the parts and settings on your pool filter you may find it daunting, so let’s take a look at the filter system.

The Parts of your Sand Filter :

1. Multiport Valve (AKA Diverter Valve)
   1. Allows you to select the setting you wish the filter to perform, changing the flow of the water depending on the position. (More on these settings a little later on)
2. Pressure Gauge
   1. This gauge is an indication of when the filter requires backwashing.  When the PSI is 8-10 above normal, it is time for a backwash.
3. Valve Tank O-Ring
4. Clamp
5. Filter Tank
   1. The filter tank holds the filter media, which should be about 2/3 of the way up the tank, although there should be a guide on the front that indicates how much media is recommended for optimum filtration.
6. Lateral Assembly (Standpipe)
7. Lateral
   1. The laterals are also known as fingers, they are very delicate but highly important to the filtration process.  They help to prevent the debris from returning to the pool, but even a hairline crack in one of these can allow the filter media to get into the pool itself.
8. Drain Cap
9. Support Stand

How it works:

When your sand filter is on Filtration the water is pumped from the pool through the pump and then into the filter.  The water will travel from the intake of the filter, through the filter media, where the debris will be caught, and then the water will go through the laterals, up the standpipe and back into the pool.

When backwashing the filter, the water comes in from the pump and down the standpipe which then pushes the water through the laterals and upwards through the filter media and takes it out the waste line, removing all the debris that the sand filter has caught previously.

And that concludes how the filter operates with regular filtration and with backwashing.  Next week’s blog we will take a more in-depth look at the settings on your multiport valve.