How does a sand filter work?

Xebec

Active member
Jun 23, 2008
32
#1
I'm curious about how a sand filter works...

Does the water seep through the sand from top to the bottom and then out to the pool? Or, does it go from the bottom of the sand to the top and then out?
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#2
In normal operation the water moves from the top down. When you backwash, water comes from the bottom up. When filtering you want gravity and water flow both working with you to help keep the sand bed compacted.
 

Xebec

Active member
Jun 23, 2008
32
#3
Thanks, Jason.

So, the water goes down through the sand and up through the center pipe and out to the pool?