10 Best 20 Gallon Aquarium Filter of December 2025

• WITH ROTATING BIO-WHEEL: Patented Bio-Wheel technology provides excellent wet/dry biological filtration.
• MULTI-STAGE FILTRATION: Delivers mechanical, chemical and biological aquarium filtration to maintain a clean aquatic environment.
• COMPATIBILITY: Use with Marineland Rite-Size Filter Cartridges (see individual filter for sizing recommendations).
• FIVE SIZES: Available in 75 GPH, 100 GPH, 150 GPH, 200 GPH and 350 GPH sizes.

MarineLand

• Hang on aquarium filter quietly delivers 100 gallons per hour of crystal clear water for your fresh or marine aquariums from 10 to 20 gallons in size.
• Revolutionary Bio-Falls Quad-Filtration system provides efficient filtration with anaerobic bacteria for additional ammonia and nitrite removal providing maximum oxygenation.
• Activated carbon cartridge removes harmful chemicals, toxins, odors, discoloration, and other contaminants for your aquarium.
• Internal sponge optimizes colonization of beneficial anaerobic bacteria and polyfiber floss cartridge traps floating particulate matter.
• Adjustable flow knob allows you to reduce filtration during feeding times or as needed. Aquarium filter is recommended for both freshwater and saltwater applications.

Penn-Plax

• Value pack includes: Aqueon Quietflow 10 filter, 4 Medium filter cartridges, 5 ammonia pads and water Conditioner sampler
• Five stage filtration: mechanical, chemical, biological, and an additional specialty pad for the cleanest, clearest, healthiest water
• Recommended for aquariums up to 20 gallons
• Self-priming - starts up automatically after cleaning or power interruptions
• High flow rates ensure a highly dissolved oxygen content or healthier, more active fish

Aqueon

• WITH ROTATING BIO-WHEEL: Patented Bio-Wheel technology provides excellent wet/dry biological filtration.
• MULTI-STAGE FILTRATION: Delivers mechanical, chemical and biological aquarium filtration to maintain a clean aquatic environment.
• COMPATIBILITY: Use with Marineland Rite-Size Filter Cartridges (see individual filter for sizing recommendations).
• FIVE SIZES: Available in 75 GPH, 100 GPH, 150 GPH, 200 GPH and 350 GPH sizes.

MarineLand

• WITH ROTATING BIO-WHEEL: Patented Bio-Wheel technology provides excellent wet/dry biological filtration.
• MULTI-STAGE FILTRATION: Delivers mechanical, chemical and biological aquarium filtration to maintain a clean aquatic environment.
• COMPATIBILITY: Use with Marineland Rite-Size Filter Cartridges (see individual filter for sizing recommendations).
• FIVE SIZES: Available in 75 GPH, 100 GPH, 150 GPH, 200 GPH and 350 GPH sizes.
• Age Range Description: all ranges
• Included Components: Marineland Penguin 100 Power Filter (upto 20 gal)

MarineLand

• WHISPER QUIET The Tetra Whisper EX Power Filter provides silent multi-stage filtration for clear clean water
• FAST SETUP Sets up easily right out of the box – no priming required
• CONTINUOUS FLOW Moves water continuously to prevent debris buildup
• NO-MESS FILTER CARTRIDGE CHANGES Design minimizes dripping to make cartridge changes easy
• SIZE This filter fits 20 to 30 gallon aquariums
• Age Range Description: All Ranges

Tetra

• UNIVERSAL DESIGN Tetra Whisper 20i Internal Filter is an all-in-one air pump and water filter system
• INTERNAL FILTER Mounts on the inside of your aquarium with clip (included)
• CATCHES DEBRIS Dense dual-sided mesh filters debris and fish waste
• AERATES WATER Air-driven design filters up to 125 GPH while oxygenating water
• CONVENIENT DESIGN Uses large easy to change Bio-Bag cartridges filter mounts inside aquarium making it possible to place tank flush against the wall

Tetra

• QUIET aquarium FILTER: The Tetra Whisper IQ Power Filter with Stay Clean technology contains a sound shield for quiet filtration less than 40 dB.
• SELF PRIMING: Submerged motor starts up with no priming required.
• STAY CLEAN TECHNOLOGY: By maintaining healthy pH levels, creates easier maintenance for healthier fish.
• CARTRIDGE REFILLS: Change cartridges monthly; uses large-sized Tetra Whisper Bio-Bag Filter Cartridges (refills sold separately).

Tetra

• Aquarium refiltration system that offers superior contact time with filter media and energy efficient pump lowers operating costs
• Quick and easy installation, we recommend that you clean aquarium filter every two weeks for maximum operation and efficiency
• Provides optimal mechanical, chemical, and biological filtrations
• Comes equipped with AquaClear Foam, Activated Carbon Filter and BioMax and Cycle Guard for superior water quality
• Filtration volume is up to 7 times larger than comparable fish tank filters
• Lifetime warranty; ideal for aquariums up to 20 gallons

Aqua Clear

• Fully submersible aquarium filter quietly delivers 110 gallons per hour of crystal clear water for your fresh or marine aquarium from 10 to 20 gallons in size.
• Activated carbon cartridge removes harmful chemicals, toxins, odors, discoloration, and other contaminants for your aquarium.
• Internal sponge optimizes colonization of beneficial aerobic bacteria. Large capacity aquarium filter cup allows you to choose your own filter medium.
• Pump head with adjustable and directional water flow. Cascade internal filters provide better filtration; physical, chemical and biological while also aerating water.
• Spray bar option allows you to distribute water evenly helping aerate your tank. Fish tank filter can be placed horizontally and is easily hidden.
• age range description: All Life Stages
• included components: Cascade Filter

Penn-Plax