Robot doesn't pick up fine dirt

[Toontje]

Hi all!

First pool, first problem so first post on this forum.

I just entered in a for us new house with a pool. All is well, all seems to be working fine, all i am doing as "maintenance" on the pool is clean it and check pH and Cl. Everything under control except for one small thing:

On the floor of the pool i lately see fine graned dirt. Looks like dust almost. When i enter the pool i can kick it up and it disappears into the water. Until it settles again on the bottom of the pool, of course.
I have a Dolphin automatic pool floor cleaning robot, but all it does is kick the dirt around. It doesn't get caught in the filter of the robot. I recently replaced the filters but i still have this issue. Someone told me it's good practice to have the mail pump running while the robot is cleaning the pool, so i do that as well.
I have cleaned the main filer of the pool by backwashing and flushing it. Can it be that what i see in the pool is residu from the main filter cleaning?
What can i do apart from manually clean it with a vacuum cleaner?

Second question, apart from following this forum, where can i read up on more in-depth info how to maintain the pool?

Thanks for your help,

Ton.

[Denniswiseman]

Try reading through this http://www.troublefreepool.com/content/ there is a stack of info there
The dirt may be to fine to pick up the dirt, try a flocculant