I had no problems with my sand, I started the tank up with the sand and it settled about a day later. What type of filter do you have? And what kind of sand? The only time I kick up sand is when I move stuff around but I don't have any problems that last so long. I'm also using play sand in my cichlid tank. Maybe your catfish kick it up a lot and that causes the sand to not settle.
i think i want a fish.