Filters · Hang-on-back
Fluval C4
Manufacturer-rated for aquariums up to 70 US gal; published maximum rim thickness is 1 inch.
Five-stage hang-on-back filter with published in-system circulation, wet/dry chamber, and quick-access media.
Consider: The mechanical frame and chemical basket lift out separately. Leave overhead access for both so cleaning does not require moving the filter.
US version, item 14003. Check what’s in the box before you buy.
Tank size Fluval rates it for
Up to 70 US gal
Choose your tank to see where it falls.
Check it against your tank →Specifications that affect fit
- Manufacturer capacity
- Up to 70 US gal
- Power
- 5 W
- Supply voltage
- 120 V / 60 Hz
- Dimensions
- 8.3 × 6.1 × 8.5 in (L × W × H)
- Pump output
- Not published
- Filter circulation
- 264 GPH
- Maximum flow
- Not published
To see what it costs to run, enter the watts on its label and your daily hours in the electricity cost calculator.
Pump output, filter circulation and maximum flow are measured in different ways. Your filter will move less water than the box says once media and hoses are in. Measure it with the flow calculator.
Before choosing this model
- Confirm item 14003 and the C4 size.
- Measure aquarium rim thickness and overhead access.
Our buying guides size it for these tanks:
A filter rated for your tank can still be too tall for your cabinet or too strong for small fish: see how to choose one.
Check it against your tank → Something not working? See the troubleshooting guide.
Choose and care for mechanical, biological and chemical media before buying replacement supplies.
Included items & upkeep
- poly/foam pad
- activated carbon
- BIOMAX
- Bio-Screen pad
Plan for the routine work
- Unplug before service.
- Follow the manual for mechanical media, impeller, seal, and replacement-part service.
To budget for replacement media and supplies, use the first-year cost calculator. For how often and how to clean it, follow the maker’s manual.