Filters · Hang-on-back
Marineland Penguin PRO 125
Marineland rates it for aquariums up to 20 US gal, with flow control up to 125 GPH.
Hang-on-back power filter with a BIO-Wheel for biological filtration, Rite-Size cartridges and flow control; Marineland says its motor is decoupled to cut noise.
Consider: It runs on Marineland’s Rite-Size cartridges, so budget for replacements; the BIO-Wheel that spins in the outflow carries the filter’s bacteria and stays in place when you change a cartridge.
US version, item AQ-78178. Check what’s in the box before you buy.
Tank size Marineland rates it for
Up to 20 US gal
Choose your tank to see where it falls.
Check it against your tank →Specifications that affect fit
- Manufacturer capacity
- Up to 20 US gal
- Power
- Not published
- Supply voltage
- Not published
- Dimensions
- Not published
- Pump output
- Not published
- Filter circulation
- Not published
- Maximum flow
- 125 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.
Before choosing this model
- Confirm item AQ-78178 and the Penguin PRO 125 size.
- Measure the gap behind the tank and the rim thickness before you buy.
What Marineland doesn’t publish
- Marineland doesn’t publish the filter’s size or its watts. Measure the gap behind your tank and the rim before you buy, and read the watts on the pump’s label before you use the electricity cost calculator.
Our buying guides size it for these tanks:
10 gallon20 gallonBetta tankShrimp tank
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
Marineland doesn’t list what’s in the box, so don’t count on any accessories being included.
Plan for the routine work
- Unplug before service.
- Follow the manual for cartridge changes and BIO-Wheel care.
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.