Do you have a lot of tank inhabitants that disturb the sandbed?
We do and that causes fine particles to float around a lot.
i bought this thank already 5 years running but its in my place only 5 month and those are loose debris from the stone.When i bust it with power had all debris are flouting but they sink down after a while. I'm able to get rid of small amount of tis debrisHow old is the tank.
I found that for a while after setup I had the same problem. The cause seemed to be that the live rock had alot fo loose debris.
After a while it stopped.
BTW I dont use filter sock or mechanical filtration of any kind, and my water is crystal clear