The 13 Best Fish Tank Filter 20 Gallon in 2023

【2-Stage Filtration System】 The hygger Bio Sponge Filter provides mechanical and biological filtration to help keep water clear and your tank healthy. Fine sponge catches fish waste and tiny debris while bio balls provide plenty space areas for the colony of beneficial bacteia

【No More Fish Getted Suck up】 This small sponge filter is fish-safe seamless design without any moving parts, protecting small fish from getted suck up. Perfect for shrimp tank, quarantine tank or fry tank

【Aerate the water】 Not only can this aquarium foam filter keep tank water clean, but also it agitates water by making bubbles. It slowly moves water around which is great for fish loves slow-flowing such as betta and fry fish

【Air Pump Driven Filter】 Like most sponge filters, it requres a at least 2w air pump & an airline (both sold separately) to run with. Convenient plastic chamber allows for quick and easy access to filter media for maintenance or replacement

【For 0.5-5 Gallon Tank】 Size S measures 1.8 in W x 5.4 in H, suggest for 0.5-5 Gallons. Size L measures 3 in W x 7.3 in H, suggest for 6-20 Gallons. Can be used at fresh and saltwater aquariums.

Dense floss removes particles and debris

Activated carbon removes toxins, odors and discoloration

Patented bio-holster removes toxic ammonia and nitrites

Diffuser grid removes additional toxins while adding oxygen for more active fish

Reduces splashing making the return exceptionally quiet

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.

CAPACITY: The Tetra Whisper IQ 20 Power Filter works in filters up to 20 gallons (130 GPH).

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).

Aquarium filtration 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 2 weeks for maximum operation and efficiency

Provides optimal mechanical; chemical; and biological filtration

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

Includes cartridge: the molded ribbed back maximizes contact with water – includes premium activated carbon.

Biological filtration: bio-foam biological filtration removes toxic ammonia and nitrites on contact.

Quiet: decoupled motor with dampeners reduces noise to below 40 db.

Powerful: impeller and motor assembly designed for efficient power usage filters 10- to 20-gallon aquariums 5 times per hour.

Sleek design: designed to fit standard aquarium hoods and canopies, the aqua-tech ultra quiet power filter makes aquatic filtration easy.

Age range description: All Life Stages

Assembled Product Dimensions: 4.00" L x 8.00" W x 7.50" H

UNIVERSAL DESIGN: Tetra Whisper 40i 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 170 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.

NOTHING LIKE OLD SCHOOL: The Clear-Free Premium Under Gravel Filter is air driven and utilizes an Air Pump (not included) to cycle crystal clear water throughout your aquarium, while keeping a crisp and neat look inside. This means there’s less “moving parts,” making for simplistic and easy maintenance. This filter is suitable for most 15 – 20 (high) gallon aquariums.

BIOLOGICAL, CHEMICAL, AND PHYSICAL FILTRATION: As air is pushed through the Air Stones and rises through the Lift Tubes, water is gently suctioned through gravel and the filter plates, allowing both air and water to pass through the Filt-a-Carb Activated Carbon Cartridges. When water continues to be drawn through, anaerobic bacteria collects and colonizes within the gravel and filter plates.

ALSO AERATES YOUR TANK: Since the Clear-Free Premium Under Gravel Filter is air driven through the use of Air Stones and an Air Pump (not included), it also aerates your tank. In essence, your aquarium is being filtered and aerated at the same time, though the same system! It’s a filter and bubbler in 1!

ITEMS INCLUDED: The Clear-Free Premium Under Gravel Filter includes 2 Filter Plates, 2 Adjustable Lift Tubes, 2 Straight Airline Tubes, 3 Filter Plate Connecters, and 2 Replaceable Filt-a-Carb Activated Carbon Media Cartridges.

MEASUREMENTS: Each Filter Plate Separately = 11.25” (W) x 11.2” (D) / Filter Plates Together = 22.5” (W) x 11.2” (D) / Each Lift Tube at Filter Plate Base = 12” – 15”

LED indicator light flashes when water cannot pass through the cartridge, generally indicating it's time to change the cartridge

Self-priming filter pump will auto-start initially or restart if power is interrupted and restored

Provides mechanical, chemical, biological and optional, additional specialty pad filtration

High flow rates for optimal dissolved oxygen content to promote healthier, more active fish

Internal pump design helps dampen noise and eliminate leaks with self-priming feature

Do not clean Bioholster when replacing the cartridge as it contains beneficial biological bacteria

Fits fresh or saltwater aquarium size up to 20 gallons

Uses One Medium Aqueon Replacement Cartridge and Size 10 Specialty Filter Pads

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

Efficiently cleans and filters water

Easy to install using suction cups and/or hanging clips

Auto-start pump requires no priming, automatically restarts if power is interrupted and restored

On average, change filter cartridge every 4 weeks

Carbon Cartridge included for chemical filtration; removes odors and discoloration from water

Bioholster included to foster biological filtration which removes toxic ammonia and nitrites

Coarse Media Sponge included for mechanical filtration; removes particles and debris

Uses Medium Aqueon Replacement Cartridges

Fits aquarium size up to 20 gallons