Since I'm new to this pool stuff (heck, we haven't even closed on the house yet) I'm just learning all I can about everything related to keeping it up. I am an old aircraft mechanic and I always want to know exactly how things work, so I will know when they don't.
OK, inside a sand filter, the laterals are what collects the cleaned water from the bottom and redeposits it back into the pool, but what exactly keeps the sand out of the laterals and going back into the pool? I would think that they have some sort of fine mesh a few microns large to keep the sand at bay. If this is so, what is the purpose of the sand? Not having a lateral handy, and I can't locate a good picture of one on the web, I am deferring to the experts-you!