The minute you add, rock, sand & water you've got about 1000+ lbs. Carpet/pad on a concrete floor shouldn't be a problem unless the concrete isn't level. If that were the case then' I'd be going after a contractor. Doubt you'll have a problem at all. When you move the stand to the spot you want check it with a level. If it's good to go then the rest is a breeze. Have fun & enjoy it. Post some pix when you get it set up.