Filtreau Excellent Combi Drum 30/40 Low Version – Gravity Fed Inline

Filtreau Excellent Combi Drum 30/40 Low Version – Gravity Fed Inline

High Capacity Long Footprint Gravity Fed Inline Drum Filter for Narrow Filter Bays

The Filtreau Excellent Combi Drum 30/40 Low Version Gravity Fed Inline is a high capacity combi drum filtration system designed for gravity fed pond installations where vertical clearance is limited but strong biological performance is required. Unlike the compact 20/25 and 25/30 models, this inline version features an extended narrow footprint, making it ideal for long filter bays positioned alongside garden walls or boundary structures.

With overall dimensions of approximately 1935mm x 590mm x 750mm, the elongated body allows installation in restricted width areas while maintaining low build height.

This model is specifically designed for koi ponds up to approximately 40000 litres. With a maximum flow rate of up to 40000 litres per hour, it bridges the gap between standard residential combi drums and the larger XL series.

The inline gravity configuration integrates directly into bottom drain systems, providing smooth pipe alignment and efficient gravity return.

High Efficiency Mechanical Filtration with Integrated UV

At the centre of the system sits a 400mm x 400mm stainless steel drum fitted with a precision 120 micron screen. This fine mesh removes suspended solids before they enter the biological chamber. By separating waste at the mechanical stage, the system protects the biological media and improves long term stability.

When debris restricts flow, the stainless steel float switch activates the automatic cleaning cycle. The industrial 130Nm SPG XL motor rotates the drum while high pressure spray nozzles clean the mesh. The internal RVS 5 bar 600W flushing pump powers the wash cycle.

As a result, the filter maintains consistent performance with minimal manual intervention.

The integrated 80W high output stainless steel immersion UV C operates at 253.7nm. It helps control green water algae and harmful microorganisms, supporting clear and healthy pond conditions without the need for an external UV unit.

Enlarged Biological Capacity and Advanced Aeration

The 30/40 Low Inline model features a significantly larger biological chamber than the 20/25 and 25/30 units. It has a suggested maximum capacity of approximately 200 litres of media. We recommend using a Charles Austen ET120 airpump.

For optimal performance, many installations use a combination of 100 to 150 litres of Hel-X moving bed media alongside several sheets of Japanese matting. This combination provides both dynamic oxygenated bio activity and stable static surface area for bacterial colonisation.

The unit is supplied without Hel-X or Japanese matting. Therefore, media must be purchased separately to match your pond’s stocking density and feeding regime.

To support the larger bio volume, the chamber is pre fitted with 4 x 300mm air bars. These ensure full oxygenation across the entire chamber and maintain constant media movement. Proper aeration prevents dead zones and reduces the risk of anaerobic bacteria forming, which is critical in koi systems.

The 130Nm SPG XL drive motor features double seals to prevent leaks and protect against moisture ingress. Meanwhile, the control box manages drum cleaning cycles for reliable long term operation.

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Key Benefits

• Long narrow inline footprint for tight filter bays
• Low height design at approximately 750mm
• Suitable for koi ponds up to approx 40000 litres
• Handles up to 40000 litres per hour
• 120 micron stainless steel drum screen
• Fully automatic self cleaning operation
• Industrial 130Nm SPG XL drive motor
• Integrated 80W high output UV C steriliser
• Internal RVS 5 bar 600W flushing pump
• Enlarged biological chamber supporting up to 200 litres of media
• Recommended 100 to 150 litres Hel-X plus Japanese matting
• Pre fitted with 4 x 300mm air bars
• 3 x 110mm inlets and 3 x 110mm outlets
• Control box supplied
• Media supplied separately

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Technical Specifications

• Maximum koi pond capacity: approx 40000 litres
• Maximum flow rate: up to 40000 litres per hour
• Dimensions: 1935mm L x 590mm W x 750mm H
• Model type: Gravity Fed Low Inline
• Inlets: 3 x 110mm
• Outlets: 3 x 110mm
• Drum size: 400mm x 400mm
• Drive motor: 130Nm 60W
• Flushing pump: RVS 5 bar 600W
• UV unit: 1 x 80W High Output immersion
• Aeration: 4 x 300mm air bars
• Control box included
• Hel-X and Japanese matting not included
• Manufacturer code: WMC31ILG

Helpful Filtreau links and compatible products

Use these links to plan the rest of the pond filtration system around your Filtreau product. The right pump, pipework, air supply, UV spares and filter media will make the installation easier to set up, maintain and service.

• View the full Filtreau range
• Browse Filtreau drum filters
• Read our drum filter guide
• Compare all drum filters
• Choose a variable pond pump
• Choose a Charles Austen air pump
• Pressure pipe, valves and fittings
• View Filtreau UV-C units
• Find replacement UV lamps and quartz sleeves