Oase BioMaster Thermo External Filter

Sale price$276.99
Size: 250 External Filter


External Aquarium Filter - For the Highest Demands

The ultimate convenience among the external filters for aquariums. The external filter meets the highest demands in water filtration and filter cleaning. The combination of highly effective biological filtering with Hel-X and mechanical/biological cleaning with filter sponges ensures healthy and clear aquarium water. The BioMaster is suitable for aquariums with a volume of 250 to 600 litres. No complete cleaning needed: the EasyClean pre-filter chamber enables convenient filter cleaning. The automatic shut-off and safety lock prevent unwanted water leaks, e.g. when removing the pre-filter module. A practical venting button makes the water suction highly effective and allows for a quick and convenient start. The complete set includes filter media, hoses, adapters, suction and discharge pipes as well as the water diffuser. The BioMaster is available with or without an adjustable heater.


  • Integrated heater – Provides precise and uniform temperature levels and reduces the amount of equipment seen inside the aquarium by housing the heater in the unit

  • EasyClean pre-filter module – Module can be removed separately from the rest of the filter. This reduces maintenance, increases filter efficiency, and extends the life of main filter foams. Customize the pre-filter with coarse 30 ppi, fine 45 ppi, ultra-fine 60 ppi, and activated carbon 45 ppi filter foams

  • No mess maintenance – Integrated safety locking features on the handle, pre-filter, and check valve in the inlet/outlet connection unit, ensure no accidental spillage or messy maintenance

  • Sealed filtration pathways – Allows for the full benefits of all four stages of filtration through this intuitive design

  • Hel-X Biomedia – An extremely large protected settlement surface (800m²/1000 liter) that allows beneficial bacteria to grow and thrive. The material is designed to stop floating as soon as it reaches a certain level of bacteria colonization.

  • Carbon pre-filter foams – Activated carbon absorbs unwanted substances in aquarium water. Carbon filter foams make replacement much simpler than using common granular carbon.

  • Adjustable flow control – Flow can be adjusted for the inlet and outlet in multiple locations on the filter assembly

  • Easy priming – Includes simple priming for fast and easy startup and continued operation

  • Quiet operation – Sound dampening design

  • What’s in the Box – Aquarium Filter with an integrated heater, filter media, intake tube with inlet strainer, water distributor nozzle, spray bar, inlet and outlet adapters with flow control, tubing, fittings, heater adapter, and power cables

  • Made in Italy, backed by German engineering

  • Fresh and marine water compatible

  • UL certified filter

  • 3 year warranty plus 1 year warranty extension with online registration


Specs BioMaster Thermo
BioMaster Thermo
BioMaster Thermo
Dimensions (in.) 9.4 x 9.4 x 14.6 9.4 x 9.4 x 16.7 9.4 x 9.4 x 19
Dimensions (mm) 240 x 240 x 370 240 x 240 x 425 240 x 240 x 480
Rated voltage 120V / 60 Hz
Power consumption, filter 15 watts 16 watts 23 watts
Power cord length 6 ft. (1.8 m)
Net weight 9 lbs. (4 kg) 10 lbs. (4.5 kg) 11 lbs. (5 kg)
Maximum flow rate 250 gph (900 l/h) 300 gph (1100 l/h) 350 gph (1250 l/h)
Maximum Head Height 5.6 ft. (1.7 m) 5.9 ft. (1.8 m) 6.6 ft. (2 m)
Connection fits 5/8" ID (16 mm)
Tubing 5/8 in. ID x 13 ft. (16/22 mm x 4 m)
Filter Volume 1.2 gal (4.4 L) 1.5 gal (5.6 L) 1.8 gal (6.8 L)
Pre-filter Volume 0.11 gal (0.4 L) 0.13 gal (0.5 L) 0.16 gal (0.6 L)
Suitable for aquariums up to max. 66 gal (250 L) 90 gal (350 L) 160 gal (600 L)
Suitable for fresh and marine water
Works with HeatUp 150 HeatUp 200 HeatUp 300

Pre-Filter Foams

The BioMaster series comes with 45 ppi activated carbon filters inside the pre-filter module. To optimize filtration OASE offers coarse 30 ppi, fine 45 ppi, and ultra-fine 60 ppi replacement foams to customize the pre-filter. All replacement pre-filter foams come in sets of six for your replenishment needs. Timing to replace the pre-filter foams varies upon aquarium size, number of fish and plants, and declines in filter performance. All BioMaster filter foams are compatible with any of the BioMaster models.

BioMaster Thermo
BioMaster Thermo
BioMaster Thermo
45 ppi Carbon Pre-Filter Foam 4 foams 5 foams 6 foams

Filter Media

The BioMaster series comes with ultra-coarse and coarse filter foams as well as Hel-x Biomedia. Since the pre-filter will do most of the filtration, these main filter foams require less frequent changes. The quantity of each filter media in the unit depends on the size of the filter. Timing to replace the filter foams varies upon aquarium size, number of fish and plants, and declines in filter performance. All BioMaster filter foams are compatible with any of the BioMaster models.

BioMaster Thermo
BioMaster Thermo
BioMaster Thermo
30 ppi Coarse Filter Foam 1 foam 1 foam 1 foam
20 ppi Ultra-coarse Filter Foam 2 foams 3 foams 3 foams
Hel-X Biomedia (0.3 gal per unit) 1 unit 1 unit 2 units