Fine dirt appears in the pool when the pump is on after vacuuming How can you remove this extra fine dirt?

There are 2 main reasons for this problem,

1, the pool filter is short on sand if the filter is more than 4 years old it would be better to empty it and replace all the sand. the volume need should be stated on the side of the filter. other wise just add some more sand to your filter so that you have about 1 fifth of the filter space left empty. this should solve the problem.

2, the dust in the pool is so fine that it works its way back through the filter to the pool. you can add aluminum sulphate or copper sulphate to the pool and this acts as a very effective clarifier for the water it will help the filter catch the small particles and make the remainder heavy and fall to the floor where they can be hoovered up.

hope this is of help to you.