Hello! So I have an Intex 22'x54" round pool with an Intex sand filter, and SWG. I am just starting to get this thing under control now, but I have always had this stuff collect in the middle. I will vacuum it out to waste and the very next day it starts again. The amount you see in the pics is after 3 days. I have replaced all my sand in the sand filter even though it is only a year old. I was thinking that maybe I need to add DE to the sand like I read somewhere on here. I thought it was algea, but even when I super shocked the pool and my FC was too high, it would still collect there. I included a pic of my enclosure because I was thinking that it might be debris, but not that much that fast! I am a newbie with the test kit, so maybe there is something I am missing....Here is the link to my pics....
https://onedrive.live.com/redir?resid=9FD930ADD7138438%21103
https://onedrive.live.com/redir?resid=9FD930ADD7138438%21103