I was happy to have a brand new liner put into my 22,000 gallon inground pool. I had to wait 5 days for the new filter to be installed after fresh water was trucked in. I went from a Hayward diatomaceous earth filter to a sand filter, because my pool company recommended it. Well, first, I have no idea what the serial number is. The installer did not put a sticker on it. He haphazardly left me the manual on the back steps, when I have a garage, a pool house and large front porch with a roof over it. It seems weaker than my old Hayward DE filter. The pool company told me some leaves got stuck in it. Now it is leaving sand in my pool. I never had that problem with my DE filter, of course. I think the filter is too small for my pool. I have only had it for about a week and a half and I want it gone and a new stronger filter put in. Has anyone had this many problems with a brand new filter before. My old workhorse filter was working fine. I was told I would love the new sand filter, and I don't love it at all. I will text my pool company tomorrow to explain the problems I have having and ask for the serial number of both the brand new filter and the brand new pump. Has anyone else had sand going into their pool from a brand new sand filter? I don't think sand is the filter for me. @