I had more options including bare bottom on the poll but when I posted it excluded a couple of them.
Its interesting to see everone's opinion on sand beds as far as being an
esthetic or functional part of our aquariums. I can't remember which magazine I read this in and my numbers might be slightly off but 75% to 80% of anoxic denitrification occure within the top 3/4 of and inch of the sand bed. I guess I'll be satisfied with my 1.5 to 2 inches.