well im back. Been reading your posts and trying not to add a post where its not necessary. Alot of good information on here. I am stuck with a problem with my sand filter. Its an old, really old pool filter and can't read the name. I vacuumed the pool twice and keep seeing dirt coming back out of the ports after it goes through the filter. Yes i plan on changing the sand this weekend. I thought i hadn't backwashed properly but guessing sand it either too old or not enough. Just replacing all of it. My main question is has someone ever tried putting an inline filter cartridge along the vacuum hose to take out the fine dirt? I see them for sale but i don't think its hard to make. Any input? PCV and some stainless hardware should do the trick. Bulk pack of cartidge filters to go with.