Many hobbyists choose to go with a substrate-free aquarium, or one that does not have a sand covered bottom, so they can better control nutrients and increase water flow. However, the look of these tanks may eventually lose their appeal and the aquarium keeper might want to go for a more natural look. To add sand to an existing setup, do so slowly. Add a little at a time so that your bio load doesn’t fluctuate out of control. A simple way of adding sand is to use a long, large diameter PVC pipe and place the end at the bottom of the tank. Pour a little sand into the tube, making sure to move it around to spread the sand out.