Charles Austen D Series Dirty-Water Pumps
Very high flow for emptying ponds, tanks, pools and flooded areas
The D Series is not an ordinary filter-circulation range. These are bottom-intake dirty-water pumps for shifting 20,000 to 56,000 litres per hour and emptying tanks, ponds or pools. A vortex impeller allows suspended solids up to 8 mm according to Charles Austen.
All three models use a 110 mm outlet. That large connection is part of the design, not an inconvenience to be reduced immediately. Choking a D60000 into small hose would sacrifice the performance that justifies buying it.
Use this range for dewatering and transfer projects where speed and solids tolerance matter. It is rarely the sensible choice for a normal garden-pond filter.
Model Comparison
| Model | Maximum flow | Maximum head | Power |
|---|---|---|---|
| D20000 | 20,000 l/h | 2.8 m | 158 W |
| D40000 | 38,000 l/h | 4.5 m | 299 W |
| D60000 | 56,000 l/h | 5.5 m | 560 W |
Maximum figures are comparison points measured under favourable conditions. Delivered flow falls as head and system resistance increase.
Bottom intake and 8 mm solids capability
The bottom intake helps the pump remove water to a low level, while the vortex design passes suspended particles up to the stated 8 mm. Large stringy material, stones and rags can still cause problems and should be cleared before pumping.
Because the D Series can move water very quickly, secure the discharge and monitor the source continuously.
The discharge system must match the pump
Plan a 110 mm route with smooth bends and a safe outlet. Confirm that the receiving area can accept the volume without erosion, flooding or contamination. A nominal 56,000 l/h is more than 900 litres per minute.
Actual output reduces with lift, but even the smaller D20000 can lower a modest pond rapidly.
Not a substitute for a filter pump
Dirty-water transfer is a different duty from continuously feeding a biological filter. D Series power and connection sizes make sense for temporary or specialist dewatering, not for a small everyday circulation loop.
Our advice: calculate where the water will go before choosing how fast to move it. The discharge route is as important as the pump.
Related Pump and Installation Categories
Charles Austen pump families · Dirty-water pumps · All pond pumps · Pond pipework
Frequently Asked Questions
Can D Series pumps pass solids?
Charles Austen states that the vortex impeller can pass suspended solids up to 8 mm.
What outlet do they use?
The manufacturer specifies a 110 mm connection across the D20000, D40000 and D60000.
Can a D60000 empty a pond quickly?
Yes. Its maximum figure is 56,000 l/h, so water level must be watched continuously.
Can I reduce the outlet to small hose?
That would create severe restriction and defeat much of the large-flow design.
Are these suitable for flood water?
They are designed for dewatering, subject to electrical safety and the type of contamination and solids present.
Can they pump string algae?
Long fibrous material can wrap or block an impeller even when smaller suspended solids can pass.
Can they be used as permanent filter pumps?
They are primarily high-volume transfer and emptying pumps; compare purpose-made filter pumps for continuous pond filtration.
How much is 56,000 l/h per minute?
Approximately 933 litres per minute at the maximum no-head comparison point.
Does maximum flow tell me what will reach the filter or waterfall?
No. Maximum flow is measured with little or no head. Lift, pipe length, fittings, hose diameter and connected equipment all reduce delivered flow.
Is maximum head the height at which I get full flow?
No. Maximum head is the shut-off end of the performance curve, where useful flow approaches zero.
Should I use the largest connection possible?
Usually yes. Generous, smooth pipework reduces friction and helps the pump deliver more water for the same electricity.
Can I reduce flow with a valve?
A valve can trim a water-pump output where the instructions allow, but a correctly sized pump or approved controller is normally more efficient than heavy throttling.
How often should I clean the pump?
Inspect it whenever flow falls and as part of routine pond maintenance. Keep the intake, rotor and impeller chamber clear without damaging seals or shafts.
Can you help size a D Series pump?
Yes. Send us the required flow, vertical lift, pipe bore and length, major fittings and the equipment the pump will feed.
Why is my real flow lower than the model name?
Model names and maximum-flow figures do not include the resistance of a real installation. A flow test at the return is the best check after installation.
