Filtomatic 25000 CWS | OASE Pond Filters - Water Garden UK
  • Filtomatic 25000 CWS Self-cleaning Filter

  • Advanced pond filter designed by OASE Engineers in Germany, the FiltoMatic 25000 filter will automatically clean itself via feedback from an intelligent digital control panel.  The control system also measures the water temperature and will regulate the amount of Ultraviolet radiation required to tackle green water issues, providing crystal clear water quality in ponds up to 25,000 Litres (approx. 5,550 Gallons).

    • Max. pond volume 25000 litres (no fish); 12500 ltrs (average fish stock e.g. goldfish); 6500 ltrs Koi
    • Produces biologically clear water with the minimum of maintenance
    • Optimum biological and mechanical cleaning reliably removes sludge, nutrients and toxins
    • Intelligent control unit monitors temperature and automatically regulates UVC and sludge disposal
    • Integrated 24 watt UVC with patented cleaning rotor and oxygen enrichment
    • Up to 40 % power savings thanks to UVC unit that is activated as needed
    • Self-cleaning function through automatic sludge discharge pump
    • OASE Clear Water Guarantee due to mechanical-biological filtration and with modern UVC technology
    • Reduces string algae by continuous removal of phosphates and nutrients
    • Guaranteed for up to 3 years (2 years standard + 1 years free of charge request guarantee)
    Find out more
    • Get a free £20 Digital Gift Voucher with this product

      To be used on your next purchase with us

  • QTY

    £463.50 inc. VAT

    £386.25 exc. VAT


The intelligent Filtomatic CWS Premium range of filters have been designed with state of the art technology to automatically remove phosphates, nutrients and toxins from the pond; thereby achieving biologically clear water, minimizing algae, including blanket weed (string algae) and creating a balanced eco-system in which fish, wildlife and plants will flourish.

Solid state monitoring and automatic control with energy efficient motor technology achieve power savings up to 40%; whilst keeping maintenance to a minimum. The addition of an Oxytex pond aerator will further improve the water quality and health of fish, other aquatic life and plants, and it will improve filter performance by up to 25%.

  • Easy installation
  • Virtually invisible as the filter device can be buried to 70 % of the device height
  • Interval cleaning, UVC and pump function can also be controlled manually
  • Easy-clean function of distinctive Oase filter foams without removal from filter housing is completed in minutes
  • Innovative control unit with display for the water temperature
  • Pond keeper selects optimum program for Koi, high, medium or low fish stocking levels
  • Low-maintenance and user-friendly.

Additional Information

Technical Info

Technical Info

OASE FiltoMatic Pond Filters - Technical Information

OASE Filtomatic
Dimensions in mm (L x W x H)
380 x 380 x 520
380 x 380 x 720
380 x 580 x 720
UVC volts/watts
Min. Filter Flow through rate
2500 litres/hr
3500 litres/hr
5000 litres/hr
Max. Filter Flow through rate
4000 litres/hr
6000 litres/hr
8000 litres/hr
Inlet hose size
1 1/2" (38mm)
Filter outlet pipe size
70 mm
Number of filter foams
Sludge pump volts/watts12v / 35W
Sludge pump max. flow rate2000 litres per hour
Sludge pump discharge pipe1 1/2" BSPM (1 1/2" hosetail provided)
Sludge pump output pressure in bar/metres
0.17 bar / 1.7m
0.2 bar / 2m
0.25 bar / 2.5m
Suitable for ponds up to maximum volume
7000 litres
14000 litres
25000 litres
Cable length10 metres
Guarantee + request guarantee2 years + 1 year f.o.c. request = 3 years (excludes UVC bulbs and foams)
Filtomatic CWS can be almost totally buried below ground
optional Filtomatic Cap
The Filtomatic CWS can be almost totally buried below ground, or in the pond itself.!
The optional Filtomatic Cap means the filter can be seamlessly integrated into the pond landscape


Filtomatic hose connectors and automatic control unit Filtomatic compact construction with secure cover
Ø1 1/2" (38mm) pump hose connections keep friction losses to a minimum, thereby maximizing pump performanceAutomatic Control Unit
The heart of the Filtomatic CWS is the control unit, which ensures automatic sludge cleaning and power savings with the timed UVC
 Secure Filter Cover
Simple one-handed opening and closing of the lid with integral locking mechanism to prevent unintentional opening.
Compact construction Ingenious design achieves optimum performance in minimum space with simple removal of internal section for easy maintenance

Oase Biokick CWS Starter Bacteria

Biokick CWS Starter Bacteria

Filtomatic in situ filter foam cleaning system

In situ Filter Foam Cleaning

Filtomatic CWS automatic sludge disposal

Automatic Sludge Disposal

All Filtomatic CWS Sets include the new Oase Biokick CWS starter bacteria. The highly concentrated micro organisms help the filter foams to form vital biomass which kickstarts the biological breakdown of harmful nutrients and toxins
Filtomatic CWS filters include Oase distinctive filter foams, with maximum surface area for beneficial bacteria, which transform toxic ammonia and nitrate into harmless nitrogen. Foams are easily and quickly squeezed clean, in situ, by the innovative compression mechanism
The Filtomatic CWS includes a unique silt separator and automated sludge disposal system. The sludge contains phosphates, the main cause of string algae, and toxins from fish waste and is removed from the pond before it can damage the eco system


Filtomatic 7000 CWS Technical Dimensions

Filtomatic filter technical dimensions

Filtomatic 14000 CWS Technical DimensionsFiltomatic 6000 & 14000 Technical Dimensions

Filtomatic 25000 CWS Technical DimensionsFiltomatic 12000 & 25000 Technical Dimensions


Performance Data

Performance Data

OASE Filtomatic Gravity, Filter Systems

Recommended pond volumes with filter outlet located at 50cms above pond water level and with 5 metres of 1 1/2" diameter hose between pump and outlet. Also performance figures given with an optional OASE OxyTex Aerator Set installed.

Filtomatic CWS Filter SetFiltomatic CWS Filter ModelIntegrated Ultraviolet ClarifierAquamax ECO Premium Pump ModelWith OxyTex Aerator in pondRecommended Pond volume in litres
No FishAverage Fish Stock 1kg/1000 litresKoi/High Fish Stock 3kg/1000 litre
Filtomatic SET 7000
Filtomatic  7000
11 watts
Aquamax Eco 4000
Filtomatic SET 7000
Filtomatic  7000
11 watts
Aquamax Eco 4000
OxyTex 400
Filtomatic SET 14000
Filtomatic 14000
24 watts
Aquamax Eco 6000
Filtomatic SET 14000
Filtomatic 14000
24 watts
Aquamax Eco 6000
OxyTex 1000
Filtomatic SET 25000
Filtomatic 25000
24 watts
Aquamax Eco 8000
Filtomatic SET 25000
Filtomatic 25000
24 wattsAquamax Eco 8000OxyTex 2000

Pond Turnover Rates: The pond stocking levels will determine the required turnover rate which in turn determines the required pump flow rate. Typically, an ornamental pond without any fish will require the pond volume to be circulated at least once every 6 hours; an average stocked pond (with up to 1 kg of fish for every 1000 litres) will require circulating once every 4 hours; a heavily stocked pond including Koi (with up to 3 kg of fish for every 1000 litres) will require circulating once every 2 hours. Filtoclear Set pump selections allow for increased pressure drop across the filter foams as they become polluted with pond waste (see the importance of regular maintenance, below).

Pump Flow Rate: The pump flow rate, typically in litres per hour (lph) or litres per minute (lpm) is determined by the vertical lift, in metres, from the surface of the pond to the outlet pipe AND by the friction losses through the system. The narrower the pipe bore the higher the friction losses, so always use the maximum hose diameter. There will also be a friction loss caused across the filter media (foams etc), which will increase as they become polluted with pond waste.

Effect of raising the filter outlet: Raising the outlet pipe height, typically for a watercourse or waterfall, will reduce the flow rate from the pump thereby increasing the amount of time it takes to circulate the dirty pond water through the filter. This effectively reduces the maximum pond volume that the filter system can cope with and may mean you will require a larger pump. Please contact us and we would be happy to advise you.

Dissolved oxygen (DO) is a major contributor to water quality. Installing an optimally sized OASE OxyTex Aerator Set will substantially improve water quality and fish and can improve filter performance by up to 25%. See the chart above for improvements in pond volume.

The importance of regular maintenance (cleaning): High flow rate = effective filtering. As the filter media (e.g. foams) remove dirt and waste from the pond, so the friction loss across the foams will increase, thereby reducing the flow rate and the effective performance of the filter. It is therefore essential, especially for those systems with a raised outlet, to keep the filter foams clean. Fortunately, this is AUTOMATIC with OASE Filtomatic pond filters.

Filtomatic 25000 CWS Self-cleaning Filter

  • £463.50 inc. VAT

    £386.25 exc. VAT

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