You must have never had a full grown red devil or flowerhorn. My 13" midas is moving gravel right now. They really enjoy moving gravel around. Like I said before, if you're going to have multiple large fish in a tank with a big bio-load go barebottom unless its going to be a "show tank." It makes it so much easier to siphon all the crap out of the bottom of the tank. Forgot to mention a big powerhead on barebottom tanks also works wonders for keeping the tank clean.