Internal 20 gal. Tank Capacity Aquarium Filters

820 results

Self-Pruning Aquarium Power Filter with LED Indicator – Up to 20 Gallon Tanks
Brand New · Unbranded
$42.97
or Best Offer
Free shipping
4/8pcs 4in Filter Sock, Filter Sock Mesh Bag for Extra Fine Aquarium Filter Bag
Brand New · Unbranded
$8.99 to $13.49
Was: $9.99was - US $9.99
Free shipping
Nano Protein Skimmer for Saltwater Aquariums, DC Pinwheel Pump for 20 Gals Fish
Brand New
$74.77
Free shipping
Aquarium Filter Sponge Filter for Fish Tank, Fish Tank Filter for Betta Shrimp
Brand New · Unbranded
$9.99 to $12.99
$1.39 shipping
21 watching
Bio Sponge Filter Breeding Fry Shrimp Fish Aquarium 10 20 50 60 Gal Qty Disc!
Brand New
$4.95 to $8.35
Free shipping
Aquarium Sponge Filter, Ultra Quiet for Betta Shrimp Fish Tank Filter 5-20 Gal
Brand New · Unbranded
$10.99 to $12.99
$0.99 shipping
Top Fin Silentstream MF20 Multi-Stage Internal Filter 20 gallon Aquarium
Brand New · Top Fin
$19.00
or Best Offer
$2.99 shipping
11 watching
Aqua-Tech Ultra Quiet Power Filter, For Aquariums 20-40 New - 20 to 40 Gallon
Brand New · AQUA-Tech
(4)
$39.99
or Best Offer
Free shipping
QANVEE Bio Sponge Filter for Shrimp Fish Tank Aquarium Crystal Red Cherry
Brand New
$14.99 to $16.99
Free shipping
inTank Chamber Two Media Basket For Fluval Evo 13.5 and Fluval Spec 16
Brand New · Fluval
(2)
$57.99
Free shipping
Corner Filter with Media for Aquariums up to 20 Gallons
Brand New
(13)
$9.29
Free shipping
Aqua-Tech EZ-Change No.2 3-Pack Aquarium Filter Cartridge (10-20 Power Filter)
Pre-Owned · AQUA-Tech
(28)
$7.99
or Best Offer
$5.94 shipping
0 bids
3d 21h
AQUEON Replacement Filter Cartridge - 3 Pack - SMALL (100106076)
Brand New · Aqueon
(35)
$12.48
Free shipping
4/8PCS 4 Inch Ring Filter Socks Aquarium Felt Filter Bags With Washable Reusable
Brand New · Unbranded
$9.99 to $13.99
Free shipping
PREMIUM UNDER GRAVEL AQUARIUM FILTER Fresh Salt Water Safe 20 - 29 Gallon Tank
Brand New · Unbranded
$26.94
Free shipping
Tetra Whisper Internal Filter 10 to 20 Gallons, with Air Pump, for Aquariums
Brand New · Unbranded
$30.02
Free shipping
2 watching
Fluval Sea Mini Protein Skimmer 5-20 Gallon - Black - 14324
Brand New · Fluval
(13)
$58.99
or Best Offer
Free shipping
Only 2 left
Top Fin 4-In-1 Filter Cartridges IF-S (2 Count) New, 2 Packs of 2
Brand New · Top Fin
$24.99
$5.86 shipping
Marina Bio-Clear Slim Filter Cartridges (Zeolite + Ceramic) S10 S15 S20 3 Pack
Brand New · Marina
(12)
$9.95
Free shipping
Ovation Submersible Power Jet Filter Replacement Filtration Pack Ovation 1000
Brand New
(2)
$9.00
or Best Offer
$5.37 shipping
Sicce Shark Internal Aquarium Power Filter 400 Advanced 106 GPH - Brand New
Brand New
(1)
$30.00
$13.70 shipping
Only 1 left!
RA Premium Under Gravel Filter - 15/20 gal (Open Box) 13154
Brand New
(1)
$59.99
Free shipping
AQUEON QUIET FLOW 20 internal shrimp filter
Brand New · Aqueon
$26.00
or Best Offer
Free shipping
2 Aqua-Tech EZ-Change Aquarium Filter #2 Cartridge 10-20G 3 Pack 5 Total Filters
Pre-Owned · AQUA-Tech
(28)
$18.95
or Best Offer
$12.59 shipping
Lot 2 Marina~Slim Filter Cartridge~BioClean~Zeolite~Fish Goldfish~New~open box
Brand New · Marina
(12)
$1.99
$6.36 shipping
AZOO OXYGEN PLUS BIO FILTER 3, INTERNAL FOAM/SPONGE FILTER COMPLETE HAS BOX USED
Pre-Owned · AZOO
$9.99
$8.99 shipping
0 bids
6d
Aqueon Replacement Filter Cartridge Small (9 Cartridges ~ Open Packages)
Brand New · Aqueon
$19.00
$0.99 shipping
Lee's Original Under Gravel Aquariums Filter
Brand New
$17.99 to $59.99
$6.99 shipping
4 watching
UV Fish Tank Filter + Pump - Eliminates Green Water in 3-7 Days, 20-75 Gallon
Brand New · Unbranded
$67.03
Was: $70.56was - US $70.56
or Best Offer
Free shipping
Filtro de potencia de acuario para peceras de agua salada y agua dulce US NUEVO
Brand New · Unbranded
$46.99
Free shipping
5 watching
QuietFlow 10 LED PRO Aquarium Fish Tank Power Filter For Up to 20 Gallon Aqua...
Brand New · Aqueon
(16)
$27.95
Free shipping
Only 1 left!
Aquarium Filter 20-75 Gallon with U-V Light Internal Pump for Fish Turtle Tank
Brand New
$94.23
Free shipping
Top Fin PF-L Large Silenstream Power FIlter Cartridges 7 (remaining) Carbon
Brand New · Top Fin
(1)
$9.51
Was: $11.89was - US $11.89
or Best Offer
$12.45 shipping
Under-Gravel Aquarium Filter Lee's Original UGF 15/20 Gallon 24"x12"
Brand New
(4)
$21.95
Free shipping
25 watching
Top Fin SF20 Aquarium Bio Replacement Sponge Filter 20 Gallon Compatible NIB
Brand New · Top Fin
$10.99
$4.99 shipping
Filtro de Acuario Pecera 200GPH de Pescados Filtración para 20-75 galones NEW US
Brand New · Unbranded
$94.99
Free shipping
Top Fin UF20 Underwater Filter System For 10-20 Gallon Aquariums
Brand New · Top Fin
$19.99
or Best Offer
$15.67 shipping
US Seller Aquarium Glass Pipe Mini Skimmer Inflow and Outflow For Mini Nano Tank
Brand New
$29.08
Was: $32.31was - US $32.31
Free shipping
20 sold
GKM3W Mini Internal UV Water Treatment for Aquariums Up to 20 Gallons
Brand New
$56.69
Free shipping
fish tank filter 10-40 gallon 40GPH dual foam canister aerating filter
Brand New · Unbranded
$35.00
or Best Offer
$12.45 shipping
TETRA Whisper IQ Power Filter 20 Gallons, 130 GPH, with Stay Clean Technology
Brand New · Tétra
(2)
$24.99
$11.71 shipping
Filter Kit upgrade for Red Sea Max Nano and Peninsula Tank. Extended Version
Brand New · Unbranded
$35.99
$6.00 shipping
Aqua-Tech EZ-Change #3 2-Packs Aquarium Filter Cartridge for 20-40 30-60 replace
Brand New · AQUA-Tech
(5)
$13.49
Was: $14.99was - US $14.99
Free shipping
Asian style Undergravel Filter Box for Shrimp: LG (Great for 20 Gallon Aquarium)
Brand New
$29.99
$9.50 shipping
Fluidized Moving Bed Filter Bubble Bio Media Filter for Aquarium Fish Tank
Brand New
$23.00 to $25.00
Free shipping
1 piece Clear Empty Refillable Inline Water Filter Cartridge RO system
Brand New
$12.00
Free shipping
Submersible 200GPH Fish Tank Filter with UV Light - Freshwater & Saltwater
Brand New · Unbranded
$66.59
Was: $73.99was - US $73.99
or Best Offer
Free shipping
Only 1 left!
# Fluval Sea Mini Protein Skimmer 5-10 US Gal- Black
Brand New · Fluval
(13)
$27.99
or Best Offer
$9.06 shipping
Aqua Clear Foam Filter Insert for 5-20 Gallon Aquariums 3-Pack 2-Pcs Lot A1390
Brand New · Aqua-Clear
(7)
$19.95
or Best Offer
Free shipping
Replacement Filter Cartridges (LARGE) 3 Pack - Aqueon
Brand New · Aqueon
(95)
$11.99
$4.99 shipping
Only 1 left!
Fluval Sea Mini 20-80L Marine & Reef Aquariums 3240 100% New
Brand New · Fluval
(13)
$37.99
$9.99 shipping
Only 1 left!
Lees Original Undergravel Filter 24 Long x 12 Wide (15-20 Gallons)
Brand New
$23.95
or Best Offer
Free shipping
4 watching
Lee's Triple-Flow Corner Aquarium Filter - Large
Brand New
(9)
$15.99
Free shipping
Top Fin Retreat Filter Large, IF-S 2 Count
Brand New · Top Fin
$10.49
Was: $14.99was - US $14.99
Free shipping
"Jet Lift" air driver - fits 1/2 inch PVC riser for aquarium Matten filter
Brand New
$7.49
$9.54 shipping
33 sold
Tetra Whisper Internal Filter with Hugger Air Pump, Tank, for Aquariums Lot
Pre-Owned · Unbranded
$29.90
or Best Offer
$46.55 shipping
ATI Hydro Sponge PRO Filter Size # 2 Course Aquarium
Brand New
$20.49
Free shipping
23 sold
10 Pcs Aquarium Filter Media Bags - Reusable Mesh Bags (6" x 4") for Fish Tank
Brand New
$10.87
Free shipping
20 sold
4 Pack Zilla Basking Platform Replacement Filter Cartridges For Aquarium
Brand New · Zilla
(11)
$38.49
Free shipping
Filtro de potencia de acuario para peceras de agua salada y agua dulce US NUEVO
Brand New · Unbranded
$73.99
Free shipping
Only 1 left!

Best selling

See All

Top Fin PF30 Silenstream Filter Cartridges
(11)
$8.79 New
Fluval Sea PS2 Mini Protein Skimmer - Black (14324)
(13)
$44.95 New
$14.00 Used
Bubble Magus Protein Skimmer Nano Qq2
$99.99 New
$59.99 Used
Marineland Penguin Power Rite-Size Filters - Size A, Pack of 6 (PA0135-06)
(74)
$17.95 New
$2.50 Used
AQUA-Tech Ultra Quiet Power Filter for Aquariums 20-40 Gallons
(4)
$39.99 New
Lees 15/20 Original Undergravel Filter 12inch by 24inch
(4)
Aqueon QuietFlow LED Pro Aquarium Power Filter 50 Starter Kit
(56)
$31.10 New
$24.99 Used
Penn-Plax Undergravel Aquarium Filter for 20 (Long) - 29 Gallon Tanks – Two 14”
$28.72 New

Top rated

See All

Marineland Penguin Power Rite-Size Filters - Size A, Pack of 6 (PA0135-06)
(74)

100% agree - Would recommend
$17.95 New
$2.50 Used
Tetra ReptoFilter Filter Cartridges Medium 90gph 3pk
(35)

100% agree - Would recommend
$4.99 New
Tetra Whisper Bio-bag Disposable Filter Cartridges Large X 8 Count
(25)

100% agree - Would recommend
RC Hagen A1394 AquaClear 50 Foam Insert - 3-pack
(16)

100% agree - Would recommend
$5.58 New
Top Fin PF30 Silenstream Filter Cartridges
(11)

100% agree - Good quality
$8.79 New
AquaClear 20-gallon Foam Inserts White 3-pack A1390
(7)

100% agree - Would recommend
$19.95 New
$3.50 Used
Tetra Whisper 20i Internal Power Filter 10 to 20 Gallons for Aquariums
(61)

100% agree - Would recommend
$23.00 New
$22.00 Used
Aqueon QuietFlow LED Pro Aquarium Power Filter 50 Starter Kit
(56)

94% agree - Would recommend
$31.10 New
$24.99 Used

Type

Review highlights

Recommended by our customers

Fish Tank Filter
By silinabarbie
I have 3 turtles that will make a tank disgusting. This filter has kept my 30 gal tank very very clean. I can see throug... see all reviews
Verified Purchase
Tetra Whisper In Tank Filter 20i With BioScrubber 20 Gallon Fish Tank Filtration
Refills correct for my filter. AquaClea...
By sigridolson85
Refills correct for my filter. AquaClear filters are good quality and last years. see all reviews
Verified Purchase
AquaClear Filter Insert Foam Size 20 - 3 Count - A-1390
Silent operating filtration device.
By fma5947-x0sltfh9
I love this filter because it works very quietly and effective mechanism with simplistic design. The entire thing can be... see all reviews
Verified Purchase
Aqueon Quiet Flow 50 Aquarium Power Filter Large Tank - No Cartridge Included
Clean Water Happy Fish
By 315beaverden
This is the only filter system that has kept the water clean and the fish alive. We have spent well over $300 in the pa... see all reviews
Verified Purchase
Marineland Penguin Power Filter Cartridges Rite-Size A (6pk)
Easy filter use at a good price
By jedplanchet
These filters are easy to assemble and change out. Very convenient and reasonably priced. see all reviews
Verified Purchase
Tetra Whisper Bio-Bag Filter Cartridge 26163 Unassembled Large 8-Pack New
great product
By jameandrew_18
they fit in easily. water look clean,does not back up flow like the other kind. see all reviews
Verified Purchase
For TopFin Filter Cartridge Silent Silen Stream Large PF-L,Small PF-S GenericPad
Aqua Clear sponges work in many other filters!
By robf123
I use Aqua Clear sponges in all my filters including brands not made by Aqua Clears. You can find a size that will fit ... see all reviews
Verified Purchase
Aqua Clear 50 (200) Foam 3pk, by Aquaclear

Internal 20 gal. Tank Capacity Aquarium Filters

Shop by category

820 results

Self-Pruning Aquarium Power Filter with LED Indicator – Up to 20 Gallon Tanks

4/8pcs 4in Filter Sock, Filter Sock Mesh Bag for Extra Fine Aquarium Filter Bag

Nano Protein Skimmer for Saltwater Aquariums, DC Pinwheel Pump for 20 Gals Fish

Aquarium Filter Sponge Filter for Fish Tank, Fish Tank Filter for Betta Shrimp

Bio Sponge Filter Breeding Fry Shrimp Fish Aquarium 10 20 50 60 Gal Qty Disc!

Aquarium Sponge Filter, Ultra Quiet for Betta Shrimp Fish Tank Filter 5-20 Gal

Top Fin Silentstream MF20 Multi-Stage Internal Filter 20 gallon Aquarium

Aqua-Tech Ultra Quiet Power Filter, For Aquariums 20-40 New - 20 to 40 Gallon

QANVEE Bio Sponge Filter for Shrimp Fish Tank Aquarium Crystal Red Cherry

inTank Chamber Two Media Basket For Fluval Evo 13.5 and Fluval Spec 16

Corner Filter with Media for Aquariums up to 20 Gallons

Aqua-Tech EZ-Change No.2 3-Pack Aquarium Filter Cartridge (10-20 Power Filter)

AQUEON Replacement Filter Cartridge - 3 Pack - SMALL (100106076)

4/8PCS 4 Inch Ring Filter Socks Aquarium Felt Filter Bags With Washable Reusable

PREMIUM UNDER GRAVEL AQUARIUM FILTER Fresh Salt Water Safe 20 - 29 Gallon Tank

Tetra Whisper Internal Filter 10 to 20 Gallons, with Air Pump, for Aquariums

Fluval Sea Mini Protein Skimmer 5-20 Gallon - Black - 14324

Top Fin 4-In-1 Filter Cartridges IF-S (2 Count) New, 2 Packs of 2

Marina Bio-Clear Slim Filter Cartridges (Zeolite + Ceramic) S10 S15 S20 3 Pack

Ovation Submersible Power Jet Filter Replacement Filtration Pack Ovation 1000

Sicce Shark Internal Aquarium Power Filter 400 Advanced 106 GPH - Brand New

RA Premium Under Gravel Filter - 15/20 gal (Open Box) 13154

AQUEON QUIET FLOW 20 internal shrimp filter

2 Aqua-Tech EZ-Change Aquarium Filter #2 Cartridge 10-20G 3 Pack 5 Total Filters

Lot 2 Marina~Slim Filter Cartridge~BioClean~Zeolite~Fish Goldfish~New~open box

AZOO OXYGEN PLUS BIO FILTER 3, INTERNAL FOAM/SPONGE FILTER COMPLETE HAS BOX USED

Aqueon Replacement Filter Cartridge Small (9 Cartridges ~ Open Packages)

Lee's Original Under Gravel Aquariums Filter

UV Fish Tank Filter + Pump - Eliminates Green Water in 3-7 Days, 20-75 Gallon

Filtro de potencia de acuario para peceras de agua salada y agua dulce US NUEVO

QuietFlow 10 LED PRO Aquarium Fish Tank Power Filter For Up to 20 Gallon Aqua...

Aquarium Filter 20-75 Gallon with U-V Light Internal Pump for Fish Turtle Tank

Top Fin PF-L Large Silenstream Power FIlter Cartridges 7 (remaining) Carbon

Under-Gravel Aquarium Filter Lee's Original UGF 15/20 Gallon 24"x12"

Top Fin SF20 Aquarium Bio Replacement Sponge Filter 20 Gallon Compatible NIB

Filtro de Acuario Pecera 200GPH de Pescados Filtración para 20-75 galones NEW US

Top Fin UF20 Underwater Filter System For 10-20 Gallon Aquariums

US Seller Aquarium Glass Pipe Mini Skimmer Inflow and Outflow For Mini Nano Tank

GKM3W Mini Internal UV Water Treatment for Aquariums Up to 20 Gallons

fish tank filter 10-40 gallon 40GPH dual foam canister aerating filter

TETRA Whisper IQ Power Filter 20 Gallons, 130 GPH, with Stay Clean Technology

Filter Kit upgrade for Red Sea Max Nano and Peninsula Tank. Extended Version

Aqua-Tech EZ-Change #3 2-Packs Aquarium Filter Cartridge for 20-40 30-60 replace

Asian style Undergravel Filter Box for Shrimp: LG (Great for 20 Gallon Aquarium)

Fluidized Moving Bed Filter Bubble Bio Media Filter for Aquarium Fish Tank

1 piece Clear Empty Refillable Inline Water Filter Cartridge RO system

Submersible 200GPH Fish Tank Filter with UV Light - Freshwater & Saltwater

# Fluval Sea Mini Protein Skimmer 5-10 US Gal- Black

Aqua Clear Foam Filter Insert for 5-20 Gallon Aquariums 3-Pack 2-Pcs Lot A1390

Replacement Filter Cartridges (LARGE) 3 Pack - Aqueon

Fluval Sea Mini 20-80L Marine & Reef Aquariums 3240 100% New

Lees Original Undergravel Filter 24 Long x 12 Wide (15-20 Gallons)

Lee's Triple-Flow Corner Aquarium Filter - Large

Top Fin Retreat Filter Large, IF-S 2 Count

"Jet Lift" air driver - fits 1/2 inch PVC riser for aquarium Matten filter

Tetra Whisper Internal Filter with Hugger Air Pump, Tank, for Aquariums Lot

ATI Hydro Sponge PRO Filter Size # 2 Course Aquarium

10 Pcs Aquarium Filter Media Bags - Reusable Mesh Bags (6" x 4") for Fish Tank

4 Pack Zilla Basking Platform Replacement Filter Cartridges For Aquarium

Filtro de potencia de acuario para peceras de agua salada y agua dulce US NUEVO

Best selling

Top Fin PF30 Silenstream Filter Cartridges

Fluval Sea PS2 Mini Protein Skimmer - Black (14324)

Bubble Magus Protein Skimmer Nano Qq2

Marineland Penguin Power Rite-Size Filters - Size A, Pack of 6 (PA0135-06)

AQUA-Tech Ultra Quiet Power Filter for Aquariums 20-40 Gallons

Lees 15/20 Original Undergravel Filter 12inch by 24inch

Aqueon QuietFlow LED Pro Aquarium Power Filter 50 Starter Kit

Penn-Plax Undergravel Aquarium Filter for 20 (Long) - 29 Gallon Tanks – Two 14”

Top rated

Marineland Penguin Power Rite-Size Filters - Size A, Pack of 6 (PA0135-06)

Tetra ReptoFilter Filter Cartridges Medium 90gph 3pk

Tetra Whisper Bio-bag Disposable Filter Cartridges Large X 8 Count

RC Hagen A1394 AquaClear 50 Foam Insert - 3-pack

Top Fin PF30 Silenstream Filter Cartridges

AquaClear 20-gallon Foam Inserts White 3-pack A1390

Tetra Whisper 20i Internal Power Filter 10 to 20 Gallons for Aquariums