Filtreau Combi 50XL Drum Filter with Built-in Rinse Pump – Gravity Fed

Filtreau Combi 50XL Gravity Fed Drum Filter with Rinse Pump and Dual 40W Amalgam UV

Includes 100 Litres of Moving Bed Media – Limited Time Upgrade

High Capacity Gravity Fed Drum Filtration with Expandable Biological Capacity

For a limited time, we are including approximately 100 litres of premium moving bed media with the Filtreau Combi 50XL at no additional cost. As a result, the system delivers strong biological capacity from day one. Consequently, it stabilises faster and comfortably supports higher feeding levels.

The biological chamber offers a total capacity of approximately 400 litres. Therefore, you can add a further 100 litres later if stocking levels increase. This gives you flexibility as your pond matures. We recommend using the Charles Austen ET100 Airpump.

The Filtreau Combi 50XL is a high capacity all in one filtration system designed for serious koi ponds up to 80m³, depending on stocking density and feeding intensity. It combines automatic mechanical drum filtration, a large moving bed biological chamber and twin 40W Amalgam UV-C units. Together, these stages provide powerful and consistent water treatment for demanding installations.

Mechanical Filtration, High Flow and UV Sterilisation

Designed specifically for gravity fed systems, the 50XL connects directly to bottom drains or skimmers. With 4 x 110mm inlets and 3 x 110mm outlets, it supports flow rates of up to 50m³ per hour. As a result, water turnover remains high and solid waste is removed quickly before it can break down.

At the centre of the unit sits a Ø520 x 420mm stainless steel drum fitted with a 120 micron screen. As debris accumulates, a stainless steel float switch detects reduced flow. It then activates the automatic cleaning cycle. Meanwhile, the integrated 5 bar rinse pump powers high pressure spray nozzles that flush waste directly to drain. At the same time, the upgraded XL SPG motor rotates the drum with consistent torque.

After mechanical separation, water enters the moving bed biological chamber. Supplied with 100 litres of media included, and expandable up to approximately 400 litres total capacity, the chamber provides substantial surface area for nitrifying bacteria. In addition, the integrated 35cm air diffuser keeps the media in constant motion. Therefore, oxygen exposure increases and ammonia and nitrite conversion improves.

Twin 40W Amalgam UV-C immersion units operating at 253.7nm provide stable sterilisation performance across varying water temperatures. Consequently, algae spores and harmful microorganisms are suppressed. This helps maintain clear water and healthier pond conditions throughout the year.

Finally, the new reinforced 15mm base plate and double sealed XL SPG drive motor ensure long term durability. Even under heavy debris loads, operation remains reliable and stable.

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Key Features

• Gravity fed drum filtration system
• 120 micron stainless steel drum screen
• Integrated 5 bar internal rinse pump
• High torque XL SPG motor with double seal
• Moving bed chamber approx. 400 litres total capacity
• ludes approx. 100 litres moving bed media
• to add further media later
• Integrated 35cm air diffuser
• Twin 40W Amalgam UV-C units
• 4 x 110mm inlets
• 3 x 110mm outlets
• Maximum flow rate up to 50m³ per hour
• Suitable for koi ponds up to 80m³

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Technical Specifications

• Model: Filtreau Combi 50XL Gravity
• Item Number: COM0050IN
• Installation Type: Gravity fed
• Maximum Pond Volume: Up to 80m³
• Maximum Flow Rate: 50m³ per hour
• Drum Size: Ø520 x 420mm
• Drum Screen: 120 micron stainless steel
• Biological Capacity: Approx. 400 litres moving bed chamber
• Included Media: Approx. 100 litres moving bed media
• Air Supply: 1 x 35cm diffuser
• Motor: XL SPG drive motor
• Flushing Pump: Internal 5 bar pressure pump included
• UV-C: 2 x 40W Amalgam immersion units
• Inlets: 4 x 110mm
• Outlets: 3 x 110mm
• Dimensions:
• Length 1270mm
• Width 900mm
• Height 1030mm

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