Both the Air-Flow 2 and Air-Flow 4 have adjustable flow rates. The air pump must be used externally above the tank. Superfish Air-Flow Mini 1.8 Watts 1 78 Litres per Hour 0 - 50 Litre. Superfish Air-Flow 1 Way 2 Watts 1 96 Litres per Hour 0 - 100 Litre.
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