The Marina Betta EZ Care Aquarium provides a no mess, no stress maintenance solution. Now there's no need to get your hands wet; disturb your Betta or disrupt your aquarium décor in order to perform routine water changes. Simply add clean water and the EZ care self-cleaning feature does the rest. By adding clean water, debris gets flushed to the bottom of the tank and then out to the reservoir located on the back. When the reservoir