Filtreau Combi-2 Gravity Drum Filter with Moving Bed and UVC

Filtreau Combi-2 Gravity Drum Filter with Moving Bed and UVC

A low-profile combi for bottom-drain and skimmer-fed systems

The Filtreau Combi-2 Gravity brings mechanical and biological treatment into a low 555 mm-high body. It is a useful option for a smaller koi-pond installation where a full-height combi would be difficult to accommodate but automatic drum cleaning is still wanted.

The drum, moving-bed section and 40W amalgam UV-C have distinct jobs: remove solids, process dissolved fish waste and control suspended algae. The internal rinse pump is included with this model, unlike the separate-pump arrangement used by the standard Filtreau drums.

Mechanical cleaning without daily screen washing

The 120-micron drum screen collects suspended waste before it reaches the biological area. A water-level change triggers the controller, operating the XL drum motor and built-in pressure-cleaning pump. The spray bar rinses the rotating screen and sends the dirt into the waste channel.

This helps keep the moving-bed section from becoming a store for debris. You still need to check the rinse nozzles, waste channel and screen, particularly during periods of heavy feeding or leaf fall. Automatic rinsing reduces routine work rather than eliminating inspection.

Media and air for the moving bed

Select biological media that suits the chamber and its retention fittings. The supplied air diffuser needs a separate air pump; choose the air supply for the actual water depth and media quantity. The goal is even movement, not a chamber so full that the media packs together.

Do not use the outside body volume as a media-fill calculation. Leave water space for circulation and allow a new media load to mature under gradually increasing feeding. Ammonia and nitrite testing are still needed even when the UV-C has made the water look clear.

Japanese matting is not a default addition to this moving-bed-only arrangement. It should only be used in a separately designed fixed-media section, not wedged into the area intended for tumbling media.

Fitting a low gravity-fed combi

The body measures 1,005 × 920 × 555 mm. Set it on a level supported base at the correct pond operating level, not simply at the same height as a previous filter. Two 110 mm inlets and one outlet need pipework that can supply and remove the intended flow without excessive draw-down.

Maximum flow is 15,000 litres/hour, with a maximum koi-pond rating of 15,000 litres. Choose below the limit where stocking and feeding demand more margin. The pump-fed Combi-2 uses a different operating arrangement and a lower maximum flow.

Technical details

Completing the installation

Allow for the circulation pump, media, air pump, valves and waste route as part of the complete system. Keep space to open the lid and service the UV lamp and quartz. A lower filter still needs overhead access once installed.

For a larger, taller gravity-fed combi, compare the Combi-NEXT with internal wash pump. Choose by the water circuit, available space and feeding load rather than the largest nominal pond rating alone.

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• Pressure pipe, valves and fittings
• View Filtreau UV-C units
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