It's too easy being green

[gregugadawg]

Sand filters only filter to about 30 microns, a human hair is smaller than this 30 microns so yeah sometimes stuff will pass through a sand filter such as algae, this is why you need to vacuum to waste when you clean up an algae pool. Or buy a d.e. filter which has one pass filtration and cleans your pool up very fast.

[waterbear]

Sand filters only filter to about 30 microns, a human hair is smaller than this 30 microns so yeah sometimes stuff will pass through a sand filter such as algae, this is why you need to vacuum to waste when you clean up an algae pool. Or buy a d.e. filter which has one pass filtration and cleans your pool up very fast.

It is generally accepted in the industry that a sand filter will filter to about 60 microns, a cartride to about 20 microns and DE to about 6 microns in normal usage. Manufacturers will make claims based on best possible conditions that don't really exist in normal usage. For some perspective on what this means the human eye can detect a particle as small as about 35 microns. A grain of table salt is about 100 microns, talcum power is about 8 microns. A slightly dirty filter will take out smaller particles than a clean one no matter the type of filter (which is why some people add DE to a sand or cartridge) but it also causes the pressure to increase faster (which limits the effectiveness faster with DE and cartridge filters more so than with sand)