Charles Austen ETD150 DSW2 and DSW1 Pond Aeration Kit

Charles Austen ETD150 DSW2 and DSW1 Pond Aeration Kit

Three diffuser heads across two positions for an uneven pond layout

This ETD150 kit combines a twin disc DSW2 station with a single disc DSW1 station. It places two thirds of the diffuser heads in the main aeration area and the remaining head at a second position. This layout is useful when two parts of the pond need different shares of the available air.

Compare the layouts in our large pond and lake aeration kit guide. The right choice depends on the shape and depth of the water, the oxygen demand and the route from the pump to each diffuser, as well as the price.

Why choose this diffuser layout?

The DSW2 carries two discs and the DSW1 carries one. At the rated pump operating point, an even allocation per head would send approximately 100 litres per minute to the DSW2 and 50 litres per minute to the DSW1. The two manifold branches therefore need different flows, not an equal split. Actual delivery depends on the depth and route to each station. Adjust and check the complete installation rather than judging the valve positions alone.

What is included?

• One Charles Austen ETD150 air pump.
• Charles Austen 1 x DSW2 and 1 x DSW1 diffuser stations, giving 3 diffuser discs in total.
• Super heavy duty weighted airline in the length selected: 30m total (2 x 15m) or 60m total (2 x 30m).
• A two way manifold with an 18 mm inlet and 14 mm valved outlets, one branch for the DSW2 and one for the DSW1; matched pump connection and hose clips.

Pump performance and diffuser airflow

The ETD150 offers 150 litres per minute at 0.15 bar with a rated power consumption of 130 W. It provides a different balance of output, purchase price and pressure from the ET100 and ET120 kits. The three diffuser heads share the available airflow; adding stations changes its distribution rather than increasing the pump output. Choose by the complete installation rather than the model number alone.

Three diffuser heads accept a combined 90 to 180 litres per minute using the manufacturer range of 30 to 60 litres per minute per head. At the ETD150 rated operating point, 150 litres per minute divided equally between three heads gives 50 litres per minute per head. This is a nominal sizing comparison, not a measured delivery guarantee. Depth, line length and diffuser resistance change the actual flow. Balance the branches to suit the number of heads on each station and check performance with the system installed.

Pump	ETD150
Rated airflow	150 litres per minute at 0.15 bar
Rated power	130 W
Pump dimensions	360 x 220 x 200 mm, length x width x height
Pump outlet connector	18 mm
Diffuser arrangement	1 x DSW2 and 1 x DSW1 diffuser stations; 3 discs

Depth and pond suitability

The 0.15 bar figure is a rated operating point, not a maximum installation depth. At 1 metre of water depth, static water pressure alone is approximately 0.10 bar; at 2 metres it is 0.20 bar and at 3 metres it is 0.29 bar. These figures exclude system losses. Water pressure increases with depth, and additional pressure is needed to move air through the airline, fittings and diffuser membranes. The pump needs to deliver sufficient air at the combined resistance of your chosen depth, airline and diffusers.

For diffuser positions around 1 to 2 metres deep, this three head layout is a candidate to assess against the actual airline routes. It is not an automatic approval for every installation at those depths. At around 3 metres, water pressure alone approaches 0.30 bar. The manufacturer curve shows the ETD150 delivering only about 90 litres per minute at that pressure, before allowing for further system resistance. That is already the combined minimum for three heads, so we recommend a pump with more pressure reserve for a three head installation at that depth.

Send us the intended diffuser depth and line lengths so we can check the complete arrangement. There is no single reliable maximum pond volume for every installation: fish loading, temperature, organic matter, circulation and the purpose of aeration all change the demand. Diffused aeration supports oxygen transfer and water movement; it does not replace filtration or guarantee clear water.

Choosing the weighted airline length

The standard option supplies 30m total (2 x 15m). The extended option supplies 60m total (2 x 30m). These are total included lengths, so allow for the distance across the bank as well as the submerged route and descent to the station. Measure the actual route rather than using the pond width alone. Longer runs increase resistance and should be checked alongside depth.

The weighted airline stays down in the pond and has a nominal half inch internal bore. Use the matched barbed connections and secure the joints with the supplied clips. Keep the pump connection and manifold appropriately sized; small aquarium airline and narrow multi outlet fittings are unsuitable substitutes for this system. Additional 30m weighted airline is available when planning a different route, but extra length should be included in the suitability check.

Installation and commissioning

Stand the pump on a firm, dry and ventilated base above the water level. Its weatherproof casing does not make it submersible or suitable for a location that floods. Keep the electrical connection dry and use a properly protected outdoor supply. Leave access for the air filter and future servicing instead of enclosing the pump in an unventilated box.

Lower the diffuser stations carefully into position and keep the discs clear of deep soft sediment. Use a suitable lowering line rather than lifting or supporting a station by its air hose. Check every connection for leakage, look for a consistent bubble pattern and adjust the branches where fitted. Keep an outlet path open while the pump is running.

Introduce bottom aeration gradually in a pond that has been stagnant or has poorly oxygenated deep water. Sudden mixing can change water conditions quickly. Where fish are already distressed, seek immediate advice rather than assuming a newly installed bottom diffuser will resolve the problem straight away.

Care and useful comparisons

Inspect the pump filter, airline and clips regularly. Reduced bubbling can indicate an air leak, a dirty membrane, a restricted line or pump wear; check the cause before adjusting valves. Follow the pump’s servicing instructions and use the correct model parts. A clean air path helps preserve performance and avoids unnecessary back pressure.

See the individual ETD150 pump and DSW2 diffuser station and DSW1 diffuser station for component information. For a different layout, compare 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.

Before ordering, send us the pond length and width, average and maximum depth, approximate volume, fish stocking and the route to each proposed station. We can help check the layout and airline option against the installation you actually have.

Compare another pump and diffuser layout

Compare our Charles Austen ET120 Twin-Zone Large Pond Aeration Kit. Check the number and position of diffuser heads, rated pressure, power and airline options against your pond before choosing.