I was told on this forum that sand is altogether a much better substrate for the well being of plant roots and the fish, especially bottom dwellers. But I have a book on tropical aquariums that says sand shouldn't be for "anything other than a base layer and it quickly compacts down and will soon eliminate oxygen from the substrate, encouraging unwanted anaerobic bacteria to flourish." Now i was planning on doing all sand with some rocks and pebbles on top to create a natural look, but i dont have any bottom dwelling fish to stir the sand, such as corys, and I'm just really confused.....any advise is greatly apppreciated