I heard that ammonia was more concentrated at the bottom of the tank. If you have bottom dwelling fish, they can suffer more.
When I change the water, I try not to disturb the gravel too much, I use a siphon, and try and get rid of all the floaty bits.
I've been changing water every second day for the last week.
I was just wondering though, would it effect the cycling process, or slow it down at all? Just a sudden thought. Anyway probably better for the fish in the long run.