Unable to filter my swimming pool water correctly: sand at the bottom

[r2d2]

Hi everybody

every day I clean the bottom of the pool (7x4) to find the same amount of "dust" at the bottom the next day!
I have the impression that the sand filter does not stop this "dust.
I completely changed the sand (13 m.cubes) coarse and fine, same thing!

I don't know what to do anymore, any ideas? THANKS

[phil59]

Too much sand?

[Christophe]

It's the sand from the sand filter...I think there is a kind of "sand net" in the filter which may have moved or is missing?

Did you just change the filter?

[r2d2]

Hello,

no actually, I changed the content of the sand filter at the beginning of the year because I had that last year too
There is no net in the sand filter? there never was one.
when loading the coarse and fine sand, I respected what was in the capacity, filter approximately 3/4 full

[Christophe]

What I call the net is actually also called a strainer: https://www.atelier-piscine.com/297-fil ... latic-side

SNTE Galatic/Jupiter Side filter strainers 18 to 33m3 (x2)

You must have a cracked or broken one?

Did you check them?

[r2d2]

Hi all
finally a clue!! thank you all
It could actually be black algae or sand, this story of the strainer in the sand filter, I had never thought about it
and seeing the result of the second sample, yes it seems to be sand?