Filters · Canister
Fluval FX4
Manufacturer-rated for aquariums up to 250 US gal.
High-output canister filter with a self-monitoring pump and a built-in water change valve.
Consider: It needs a 15.75 × 15.75 inch patch of cabinet floor and room above to lift the lid. Measure the inside of the cabinet, between any center brace and the door frame, before choosing it.
US version, item A214. Check what’s in the box before you buy.
Tank size Fluval rates it for
Up to 250 US gal
Choose your tank to see where it falls.
Check it against your tank →Specifications that affect fit
- Manufacturer capacity
- Up to 250 US gal
- Power
- 30 W
- Supply voltage
- 120 V / 60 Hz
- Dimensions
- 15.75 × 15.75 × 16.5 in (L × W × H)
- Pump output
- 700 GPH
- Filter circulation
- 450 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
- Measure the cabinet floor (15.75 × 15.75 in) and height, plus the hose route.
- Compare circulation (450 GPH), not pump output (700 GPH), across filters.
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
- Bio-Foam (4)
- Bio-Foam+
- BIOMAX (2)
- carbon foam pad
- media bags (2)
Plan for the routine work
- Unplug and close the valves before opening.
- Follow the manual for priming, impeller access, and media order.
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.