Using Fish Gear Aquarium Glass Gems Gravel is easy! First, rinse the gravel thoroughly with cold water until the water runs clear and there's no debris or color left. Remember, never use soap or detergent. When filling your tank with water, place a saucer on the gravel and pour the water onto the saucer. This way, the water won't mess up your new gravel. Once your aquarium is up and running, use a gravel vacuum for regular cleaning. But be careful! Make sure to choose the right gravel for your fish. Some fish might not do well with gravel and are better off with sand or in a bare - bottom aquarium. Also, gravel can be a choking hazard for some fish. Keep in mind that due to lighting and other factors, the actual color of the gravel might be slightly different from what you see in the image.