We now have two series.
The SW series is used for the shallow ponds up to 1/2 acre and 8′ deep.
The PL series is used for larger and deeper ponds. Ponds up to 4 acres and 21′ deep
Airline comes in 3/8″ and 5/8″ depending on the size of the system.
The deeper a diffuser plate is placed in your pond, the more area it can effectively aerate.
Shallow ponds, or ponds with irregular shapes & bends, require more diffuser plates per surface area.