Filtreau Excellent Bio Drum 25 – Gravity Fed

Filtreau Excellent Bio Drum 25 – Gravity Fed

A compact automatic mechanical stage for gravity-fed filtration

The Excellent Bio Drum 25 Gravity is a useful starting point when you want a compact automatic drum within a wider pond-filtration design. It combines a 400 mm-diameter drum, internal pressure-cleaning pump and 80W high-output UV-C in a body only 530 mm wide.

The gravity-fed arrangement places the filter before the circulation pump. Bottom-drain and skimmer water reaches the dirty side of the screen first, allowing solids to be removed before that water is pumped onwards.

Automatic separation of suspended waste

The 120-micron screen collects solid material as water passes through. A change in water level starts the cleaning cycle: the drum turns while the internal wash pump supplies the spray bar, rinsing debris into the waste channel.

This reduces repetitive hand-cleaning of mechanical media. It still needs a clear waste route and routine checks of the screen and nozzles. A level-triggered cleaning system cannot correct a blocked inlet or return elsewhere in the pond circuit.

Its place in the complete filter system

Clear water and healthy water need three complementary jobs: the drum removes suspended solids, UV-C helps control green water, and mature biological media processes ammonia and nitrite. Match the biological stage and its air supply to your fish stock and daily feeding, while allowing enough flow through the whole system.

If you want clearly separated moving-bed and matting chambers within the same filter package, compare the Excellent Combi 20/25 Low Gravity. If retaining a separate biological stage, check its permitted flow and water-level relationship with the drum before choosing the circulation pump.

Compact dimensions, useful access

The body is 1,163 × 530 × 680 mm. That narrow footprint can make a difference in a restricted filter area, but leave clearance to open the lid, reach the waste channel and remove the UV lamp and quartz. Do not build fixed walls or pipework across the service route.

Maximum water flow is 25,000 litres/hour. Three 110 mm inlets and two outlets need pipework with enough capacity to avoid excessive draw-down. An adjustable circulation pump helps set the final operating point once the system is filled and tested.

Technical specification

Comparing the next size and looking after the unit

The Bio Drum 35 Gravity uses a wider 500 mm drum while keeping the same body length and height. The pump-fed Bio Drum 25 is for a different water circuit and has a lower maximum flow.

Use the Excellent manual for safe maintenance. Keep the correct HO lamp reference rather than substituting an amalgam lamp solely because both say 80W. Inspect screen condition and waste drainage regularly, with the electrical supply isolated before reaching inside the housing.

Related equipment and advice

• 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
• Filtreau Excellent Bio Drum 100 – Gravity Fed