Pond Air 4 SystemPond air systems are quiet and are simple to use and maintain. Air Kits come equipped with weighted air stones, air line, and check valves. Pond Air 4 comes with four air stones (2 inches in diameter), 30 ft of airline, and 8 watts. Pond Air Aeration Kits circulate the water from the bottom of you water garden to the top, creating a hole in the ice during winter months. This hole in the ice allows harmful gases from organic decomposition to escape. In