Filtreau Excellent Combi Drum 25/30 Low Version – Gravity Fed

Filtreau Excellent Combi Drum 25/30 Low Version – Gravity Fed

Full combi treatment with a lower filter body

The Excellent Combi 25/30 Low gives a gravity-fed koi pond a full mechanical and biological filtration layout in a 750 mm-high body. It is a useful option where the available height rules out a taller filter, but you still want separate treatment stages and a proper automatic cleaning system.

Its 1,300 × 1,117 mm footprint is wider than the 25/30 Low Inline, so choosing between them is as much about the shape of the filter area as pond volume. The ordinary Low model is shorter front to back; the Inline trades width for length.

Why the filtration stages are separate

The drum screen takes solid waste out before it reaches the media. A float-triggered rinse rotates the drum and uses the built-in pressure-cleaning pump to clear the screen. Waste leaves through its own discharge route, reducing the amount of debris left in the biological chambers.

The 80W high-output UV-C helps clear suspended algae. Behind the mechanical stage, aerated moving-bed media supports ammonia and nitrite conversion, while Japanese matting belongs in the static-media section. Neither the UV nor a clean screen replaces a mature biological filter, so water testing remains important as stocking and feeding increase.

Media that can be maintained properly

Hel-X and matting are selected separately. The optional 100-litre Hel-X and 2 m² matting arrangement is a reference for configuring the chambers, not a rule to fill the whole body with media. Overfilling a moving bed makes it harder to achieve even movement and leaves less room for water and air to pass through.

For the matting option we use our high-quality Japanese matting, supplied as 1.2 × 1 m uncut sheets. One or two sheets can be selected; two give 2.4 m² before trimming. Check the chamber layout before cutting and leave passages between the pieces. A factory cartridge is a different product, not simply two sheets bundled together.

The fitted air bars need a separate air pump. We can help choose from the pond air-pump range once the media quantity and working depth are known. Headline litres/minute alone do not tell you how much air reaches the bottom of the chamber.

Pond size and usable flow

This gravity-fed version handles up to 30,000 litres/hour, with a maximum koi-pond rating of 30,000 litres. The general-pond figure is higher because fish and feeding loads differ. Use the koi figure as an upper selection guide, then allow margin for your own stocking rather than working at the limit from day one.

Model specifications

Fitting a low filter correctly

Low body height does not mean the filter can sit at any level. Set it against the intended pond operating level and the model-specific installation drawing, with a stable, level base beneath the whole footprint. Plan each bottom-drain and skimmer branch so one restricted line does not limit the rest of the system.

Keep the UV service route, waste channel and lid accessible. Check the spray nozzles and screen during routine maintenance, and use the manufacturer's operating manual rather than pressure-washing the mesh. If the filter will be fed by a pump in the pond, the correct companion is the 25/30 Low Pump Fed.

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