An Aqueon Gravel Vacuum is an essential for all hobbyists. Gravel vacuums allow for easy and safe cleaning of an aquarium. It is a must have for any aquarium in order to remove waste from the bottom of the aquarium without having to empty out all of the water. Empying all of the water can result in a buildup of ammonia and nitrites which can kill your betta. This gravel vacuum will be an efficient cleaner for tanks from 1-15 gallons. No more than 75%-50% of tank water should be removed at one time.