For decades, EHEIM has been regarded as one of the most trusted names in aquarium filtration. Renowned for German engineering, reliability, quiet operation, and exceptional biological filtration, EHEIM external filters are a popular choice for both freshwater and marine aquariums.
Whether you’ve just purchased your first EHEIM filter or you’re looking to troubleshoot an existing unit, this technical help guide covers everything you need to know about setup, maintenance, media configuration, common issues, and long-term care.
Why Choose an EHEIM External Filter?
EHEIM external filters have earned a loyal following thanks to their combination of simplicity, performance, and durability.
Benefits include:
- Exceptional reliability
- Long service life
- Quiet operation
- Excellent biological filtration
- Low energy consumption
- High-quality replacement parts availability
- Wide range of models for different aquarium sizes
Many aquarists continue to run EHEIM filters successfully for well over a decade with proper maintenance.
Understanding the EHEIM Filter Range
EHEIM Classic Series
The Classic range remains one of the most respected filter lines in the aquarium hobby.
Popular models include:
- EHEIM Classic 150 (2211)
- EHEIM Classic 250 (2213)
- EHEIM Classic 350 (2215)
- EHEIM Classic 600 (2217)
These filters are known for:
- Simple design
- Proven reliability
- Excellent biological filtration
- Minimal maintenance requirements
EHEIM Experience Series
The Experience range builds upon the Classic platform with additional convenience features.
Benefits include:
- Integrated media baskets
- Easier maintenance
- Improved media organisation
- Compact footprint
EHEIM Professionel Series
The Professionel range is designed for aquarists seeking maximum performance and convenience.
Features include:
- Integrated priming systems
- High flow rates
- Advanced media configurations
- Superior energy efficiency
- Optional electronic control on selected models
EHEIM Professionel 5e
The flagship EHEIM filter range offers:
- Electronic flow control
- WiFi connectivity
- Custom performance settings
- Intelligent monitoring systems
- Ultra-quiet operation
Ideal for high-end planted aquariums and large freshwater systems.
How EHEIM External Filters Work
EHEIM filters use a multi-stage filtration process designed to maximise water quality.
Mechanical Filtration
The first stage removes physical waste such as:
- Fish waste
- Uneaten food
- Plant debris
Common media include:
- Coarse filter pads
- Fine filter pads
- Mechanical filter floss
Biological Filtration
Beneficial bacteria colonise biological media and convert harmful ammonia and nitrite into nitrate.
Popular EHEIM biological media include:
- EHEIM Substrat Pro
- EHEIM BioMech
- Ceramic rings
This is the most important stage of filtration.
Chemical Filtration
Chemical media can be added when required to remove specific contaminants.
Examples include:
- Activated carbon
- Phosphate removers
- Specialty resins
Many aquarists only use chemical media temporarily.
Recommended EHEIM Media Layout
Correct media arrangement improves filtration efficiency.
Bottom Layer
Coarse mechanical filtration:
- Ceramic rings
- BioMech
Middle Layers
Biological filtration:
- Substrat Pro
- Biological media
Top Layer
Fine mechanical filtration:
- Fine pads
- Filter floss
Optional Chemical Media
If used, position chemical media after mechanical filtration but before final polishing pads.
Setting Up an EHEIM External Filter
Step 1: Position the Filter
Place the filter below aquarium water level inside the cabinet.
This allows gravity to assist priming and operation.
Step 2: Install Hoses
Avoid sharp bends or kinks in the tubing.
Keep hose runs as short as practical to maximise flow.
Step 3: Install Media
Arrange media according to the recommended flow direction for your specific model.
Step 4: Prime the Filter
Depending on the model:
- Use the integrated priming button.
- Fill hoses manually.
- Fill the canister with aquarium water before startup.
Step 5: Start the Filter
Check:
- Water flow
- Hose connections
- Seal integrity
- Air removal
Allow trapped air to purge naturally during initial operation.
EHEIM Maintenance Schedule
Regular maintenance keeps your filter operating efficiently.
Every 2–4 Weeks
- Clean intake strainers
- Inspect hoses
- Remove visible debris
Every 4–8 Weeks
- Rinse mechanical media
- Clean pre-filters
- Remove sludge buildup
Every 3–6 Months
- Clean impeller assembly
- Clean impeller well
- Inspect O-rings
- Check hose condition
Annually
- Replace worn seals
- Inspect impeller shaft
- Review media condition
Common EHEIM Filter Problems and Solutions
Reduced Flow Rate
Possible Causes
- Dirty filter media
- Blocked hoses
- Dirty impeller
- Clogged intake strainer
Solution
Perform a complete maintenance service and clean all water pathways.
Excessive Noise
Possible Causes
- Air trapped inside the filter
- Dirty impeller
- Worn ceramic shaft
- Incorrect installation
Solution
Clean the impeller assembly and ensure all air has been removed from the system.
Filter Not Priming
Possible Causes
- Airlock in tubing
- Incorrect hose positioning
- Blocked intake
Solution
Check hose routing and ensure the filter is positioned below aquarium level.
Water Leaks
Possible Causes
- Damaged O-ring
- Dirty gasket
- Improperly seated seal
Solution
Clean all sealing surfaces and replace worn seals if necessary.
How to Clean an EHEIM Impeller
The impeller is the heart of the filter and should be cleaned regularly.
Cleaning Procedure
- Disconnect power.
- Remove the impeller cover.
- Carefully remove the impeller assembly.
- Clean debris from the impeller blades.
- Clean the impeller well using a suitable brush.
- Reassemble carefully.
A dirty impeller is one of the most common causes of reduced flow and increased noise.
Best Media Upgrades for EHEIM Filters
Many hobbyists customise their EHEIM filtration system.
Popular upgrades include:
EHEIM Substrat Pro
Provides excellent biological filtration thanks to its highly porous structure.
Seachem Matrix
A popular alternative biological media with exceptional surface area.
Fine Polishing Pads
Improve water clarity by trapping fine particles.
Purigen
Helps maintain crystal-clear water by removing dissolved organic compounds.
Maximising EHEIM Filter Performance
To get the best results:
- Avoid over-cleaning biological media.
- Maintain consistent water changes.
- Clean hoses periodically.
- Keep impeller assemblies clean.
- Use high-quality biological media.
- Avoid excessive fish stocking.
These simple steps can dramatically improve filtration performance and longevity.
Frequently Asked Questions
How Long Do EHEIM Filters Last?
With proper maintenance, many EHEIM filters remain operational for 10–20 years or longer.
How Often Should I Replace Substrat Pro?
Substrat Pro can often remain effective for many years when cleaned properly.
Can EHEIM Filters Be Used on Marine Aquariums?
Yes. EHEIM filters are widely used on both freshwater and marine systems.
Why Is My EHEIM Filter Making Noise?
The most common causes are trapped air, impeller contamination, or wear on the impeller shaft.
Final Thoughts
EHEIM external filters have earned their reputation as some of the most reliable filtration systems available. Whether you’re running a Classic, Experience, Professionel, or Professionel 5e model, proper maintenance and media selection will help ensure years of reliable operation and outstanding water quality.
At Charterhouse Aquatics, we stock the full range of EHEIM external filters, replacement parts, filter media, hoses, seals, impellers, and accessories. If you need help selecting, maintaining, or troubleshooting your EHEIM filter, our expert team is always available to help.
