Charles Austen ET120 Twin-Zone Large Pond Aeration Kit

Charles Austen ET120 Twin-Zone Large Pond Aeration Kit

The higher-output twin-zone choice, delivering up to 60 L/min to each DSW1 before system losses.

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 two-zone ponds needing slightly more airflow or longer runs than the ET100 kit.

Why this layout works

• Adds useful airflow headroom for slightly larger ponds or more demanding two-zone layouts.
• Depth and airline resistance normally bring each DSW1 closer to its preferred working flow.
• Independent valves allow the two lines to be balanced when their lengths or depths differ.

What is included

• 1 x Charles Austen ET120 air pump
• 2 x DSW1 single-disc diffuser stations
• 1 x 2-way manifold with 18mm inlet and 14mm valved outlets
• 2 x 15m lengths cut from one 30m reel
• Correctly sized connectors, reducers, stainless steel hose clips and installation guidance

Airflow, pond size and depth guide

Every pond is different. Treat these figures as a sensible starting point rather than a guaranteed maximum. Actual airflow is affected by diffuser depth, airline length, fittings, pond shape, water temperature, fish load and the purpose of the aeration. The pond-volume guide uses an initial allowance of 3–6 L/min per 1,000 litres before system losses; the lake-area guide assumes 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: 2 x 15m lengths cut from one 30m reel. Choose the extended option for 2 x 30m lengths (60m total). 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
• 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
• ET250 Central DSW4 – 1 x DSW4 four-disc diffuser station
• 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.

Compare ETD aeration kits for shallower installations

The ETD range provides additional pump and diffuser combinations where lower operating pressure suits the pond. Compare the diffuser positions and included airline lengths, then check the depth and route against the pump performance.

• ETD200 Central DSW4 Pond Aeration Kit
• ETD200 Twin DSW2 Pond and Lake Aeration Kit
• ETD200 Four Zone DSW1 Pond Aeration Kit
• ETD150 Three Zone DSW1 Pond Aeration Kit
• ETD150 DSW2 and DSW1 Pond Aeration Kit

The ETD200 is rated at 200 litres per minute at 0.15 bar. The ETD150 kits share the available airflow between three diffuser heads, either across three DSW1 stations or a DSW2 and a DSW1. Compare all large pond and lake aeration kits for the full choice of layouts.