Lee'sUltimate GravelVac® Cleaning Kit Maintaining a healthy, happy aquarium. Twenty-five percent water changes should be performed at least once a month in order to maintain a healthy aquatic environment. Aquarium maintenance work is no longer a labor intensive work. With Lee’s Ultimate Gravel Vac® the job just becomes much easier. Now you don’t need to use those heavy, messy buckets. It attaches directly to most faucets and the hose allows water to drain directly into the sink and refill is a breeze. The regular water changes refresh your aquarium with precious nutrients and remove excess debris/fish waste, uneaten food and decomposed plant matter.