My guess is that it is most likely just dirt. I see the same thing in my liner pool. When you vacuum, the movement of the vacuum head causes some of the dirt to get into the suspension of the water. Then, later when the water quiets back down, the dirt drops back to the floor. You have to move the vac head REALLY slowly to avoid this and even then, it is impossible to prevent it totally.
When you backwash, always rinse.
What size is your pump and what size is your sand filter (how many lbs of sand does it hold)?
Bookmarks