Kasco Surface AeratorSurface Aerators are prefect for a pond or lake that is fairly shallow (2 5 ft deep) or is heavily stocked with fish. Low oxygen levels result in costly and devastating death of fish in your pond. Increasing the oxygen transfer can help to prevent those situations from happening. High volume units focus on moving the maximum amount of water. The maximum water movement promotes high oxygen transfer in the water. A 50' cord length is standard. Surface