Can't get bottom clean

[CarlD]

Two other things:

Your filter isn't filtering the finest stuff.
Your vacuum isn't picking up the finest stuff.

Or you are getting lots of pollen because it's that time of year.

[rainhill]

How do I know if my filter is filtering correctly? When should I add new sand to my filter?

[ivyleager]

Or you are getting lots of pollen because it's that time of year.

Down here in the South, the pollen hit a month ago. No pollen problems now.

CaryB