Charles Austen ET250 Central DSW4 Pond Aeration Kit

Charles Austen ET250 Central DSW4 Pond Aeration Kit

A higher-output central kit that maintains strong airflow to one DSW4 station for deeper installations.

This complete system combines a land-mounted linear air pump, self-sinking diffuser stations, weighted airline, flow control and the secure fittings needed for a properly planned large-pond or lake installation. It is best suited to a high-output central plume where a little more airflow is useful but a second station is not practical.

Why this layout works

• The DSW4 provides four discs in one compact central station.
• A full-bore 26mm connection keeps restriction low and helps preserve airflow as diffuser depth increases.
• The 26mm pump outlet remains unrestricted until the final DSW4 connection.

What is included

• 1 x Charles Austen ET250 air pump
• 1 x DSW4 four-disc diffuser station
• 1 x 26mm-compatible full-bore connection assembly with secure reducers and clips
• 1 x 30m super-heavy weighted airline
• Correctly sized connectors, reducers, stainless steel hose clips and installation guidance

Important: Never close or obstruct the diffuser feed while the pump is running. This kit must be supplied with its specified full-bore connection assembly.

Airflow, pond size and depth guide

Every pond is different. These figures are deliberately described as screening guidance, not guaranteed maximum coverage. Actual airflow is affected by diffuser depth, airline length, fittings, pond shape, water temperature, fish load and the purpose of the aeration. Stocked-pond figures use an initial 3–6 L/min per 1,000 litres approach before system losses; lake area figures assume a reasonably regular water body with light-to-moderate loading and sensible diffuser placement.

Diffused aeration supports oxygen transfer and moves water vertically, but it does not replace adequate filtration and it is not, by itself, a guaranteed algae treatment.

Choose the airline length

Standard: 1 x 30m super-heavy weighted airline. Choose the extended option for 2 x 30m reels joined for a 60m run. The product selector prices the extra weighted airline and any required straight joiners automatically.

The super-heavy airline has a nominal 12.5mm (1/2-inch) internal diameter. Its flexible bore fits securely over the specified 14mm or 1/2-inch barbed outlets. Every connection must be secured with the supplied stainless steel hose clip. For runs outside the listed options, add extra 30m weighted airline or ask us to calculate the most efficient layout.

Installation and safe start-up

• Position the air pump on a firm, dry, ventilated base above the water level, or use a correctly rated non-return arrangement where this is impossible.
• Use an outdoor electrical supply protected by a 30mA RCD and keep electrical connections out of the water.
• Keep manifold and trunk connections full-bore; avoid unnecessary reductions that create back pressure.
• Place diffuser stations level and use the valves to balance visible bubble output. Never lift a diffuser by its airline.
• In an older, stagnant or strongly stratified pond or lake, introduce bottom aeration gradually. Rapidly mixing poor-quality deep water through the whole water column can temporarily reduce oxygen and stress fish.
• Clean diffuser membranes and inspect airline, clips and pump filters regularly. Service the pump with the correct diaphragm and filter kit.

Compare the complete aeration kit range

See the Large Pond & Lake Aeration Kits guide, or compare another layout:

• ET100 Twin-Zone – 2 x DSW1 single-disc diffuser stations
• ET120 Twin-Zone – 2 x DSW1 single-disc diffuser stations
• ET200 Central DSW4 – 1 x DSW4 four-disc diffuser station
• ET200 Twin DSW2 – 2 x DSW2 twin-disc diffuser stations
• ET200 Four-Zone DSW1 – 4 x DSW1 single-disc diffuser stations
• ET400 Twin DSW4 – 2 x DSW4 four-disc diffuser stations
• ET400 Four DSW2 – 4 x DSW2 twin-disc diffuser stations
• ET500 Twin DSW4 – 2 x DSW4 four-disc diffuser stations
• ET500 Four DSW2 – 4 x DSW2 twin-disc diffuser stations

Free suitability check before you order

Send us the pond’s length and width, average and maximum depth, approximate volume, fish type and stocking level, distance from the pump to each diffuser position, and whether the main goal is fish oxygen support, circulation, de-stratification or emergency aeration. We will check the pump, diffuser count and airline layout before dispatch.