Got a pool question for adjectives you pool techs? I have an above ground pool and I have a sand filter....

I have an above ground pool and I have a sand filter. My first query is, how do they work? Can you give me a website or picture that shows how they work? Also, why is there sand contained by the pool after this was installed? I'm guessing this isn't normal.
Window grilles ?
Answers:    Simple. They work by pumping hose through the sand from the top of the filters and out the bottom through small plastic filters, another word for the filter is fingers. These fingers are your problem. At the bottom of the filter are these fingers that the sand is packed around and filled above. Either you enjoy a cracked one or the filter wasnt filled to the right hight inside the filter. If there isnt adequate sand in the filter, the agitation of the water will stir up the sand and lead to the sand to pass through the fingers. It is possible to get some sand through at start up. So, if you verbs to have problems you need to spread out the filter, check the level, (about 3/4 full). If it is filled to the right horizontal, you need to scoop out the sand and inspect the fingers at the bottom of the filter. They can be unscrewed and replaced.

Good Luck!