Air Pump Manifolds with 18mm Inlet and 4mm Outlets

Air Pump Manifolds with 18mm Inlet and 4mm Outlets

Air manifolds for splitting one larger pond air pump into multiple 4mm airline runs

These Air Pump Manifolds are designed for pond aeration systems where one larger air pump needs to supply several smaller 4mm airline runs. Each manifold has an 18mm inlet for connecting to the outlet hose from a suitable pond air pump, then splits that airflow across multiple 4mm outlet taps.

This makes them a practical choice for installations using several small air stones, tank aeration points, quarantine vats, filter chambers or individual diffuser points. Instead of trying to run several separate air pumps, one correctly sized pump can be split through the manifold and balanced using the individual taps.

The key advantage of using a manifold is control. Each outlet can be adjusted independently, helping you balance airflow between different areas of the pond or filter. This is useful when some air stones are deeper than others, when one line is longer than another, or when a filter chamber needs a different air output to a pond diffuser.

Available options

Option	Inlet size	Outlet size	Typical use
6 Way	18mm inlet	Six 4mm outlets	Smaller multi outlet systems, quarantine tanks and filter chambers
8 Way	18mm inlet	Eight 4mm outlets	Multiple air stones, treatment vats and smaller aeration points
10 Way	18mm inlet	Ten 4mm outlets	Larger split systems where one air pump supplies many small airline runs

Key benefits

• 18mm inlet for connecting to a suitable larger pond air pump outlet hose
• 4mm outlet taps for smaller airline, air stones and compact diffuser points
• Available in 6 way, 8 way and 10 way versions
• Individual taps allow each airline run to be balanced separately
• Helps keep aeration systems neater and easier to service
• Useful for quarantine systems, holding vats, filters and multiple air stone installations
• Reduces the need for several separate small air pumps

Technical specifications

• Product type: Pond air pump manifold
• Inlet size: 18mm
• Outlet size: 4mm
• Available versions: 6 way, 8 way and 10 way
• Outlet control: Individual taps on each outlet
• Suitable for: 4mm airline, small air stones, quarantine systems, filter chambers and small diffuser points
• Important note: Match the total number of outlets and air stones to the output of your air pump to avoid excessive back pressure.

Choosing the right manifold

Use this 18mm inlet and 4mm outlet manifold when you are splitting air to several smaller 4mm airline runs. If you are running larger airline to bigger diffuser discs, weighted lake diffuser stations or longer underwater airline runs, use a larger outlet manifold instead, such as the 2 Way Air Manifold with 8mm to 14mm Outlets or 4 Way Air Manifold with 8mm to 14mm Outlets.

Related aeration products

• Standard Sinking Airline
• Ceramic Air Stones
• Ceramic Flat Air Discs
• Evolution Aqua Heavy Duty Sinking Airline
• Super Heavy Duty Weighted Airline

Related 8mm outlet manifold

For systems that need one larger inlet feeding four 8mm outlet lines, see the 4 Way Air Manifold with 8mm to 14mm Inlet and 8mm Outlets. It is useful when a main 8mm, 10mm, 12mm or 14mm air feed needs to be split neatly to four 8mm diffuser or airline runs.