Filters · Hang-on-back

Fluval AC50

Manufacturer-rated for 20–50 US gal aquariums.

Four-stage hang-on-back filter with adjustable flow, a reusable media basket, and maker-rated maximum flow.

Consider: The media basket lifts upward. Leave unobstructed space above the filter so routine cleaning does not require moving the tank.

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US version, item 19610. Check what’s in the box before you buy.

Rated for a 20 gal tankDrawn to scale on a 20 gallon long (example). Body 4.4 in deep and 6.4 in tall, hung on the back rim; check the gap behind the tank and the lid cut-out.

Tank size Fluval rates it for

20 to 50 US gal

Choose your tank to see where it falls.

Check it against your tank →

Specifications that affect fit

Manufacturer capacity
20–50 US gal
Power
7 W
Supply voltage
120 V / 60 Hz
Dimensions
7.2 × 4.4 × 6.4 in (L × W × H)
Pump output
Not published
Filter circulation
Not published
Maximum flow
200 GPH

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.

Choosing between sizes

This model’s range is 20–50 US gal; Fluval AC20 is 5–20 US gal. Maximum flow differs: 200 versus 100 GPH. Choose by your tank size and the space you have, not by the family name.

AC20: details and fit →

Before choosing this model

  • Confirm item 19610 and the AC50 size.
  • Measure rear and overhead clearance before buying.
  • The manual lists a maximum aquarium rim thickness of 0.9 inches / 2.4 cm. Measure your tank rim before buying.

Our buying guides size it for these tanks:

20 gallon29 gallon40 gallon

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
  • carbon
  • BIOMAX
  • intake sponge

Plan for the routine work

  • Unplug before service.
  • Follow the AC manual for media order, basket service, and impeller cleaning.

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.

Manufacturer instructions

Compared with