20 models · Specs last checked July 2, 2026

Which aquarium filter should you actually buy?

With no preferences selected: Fluval FX6 High Performance Canister Filter comes first in this spec comparison. The first fit with an Amazon link is Fluval AquaClear 110 Power Filter.

Fluval AquaClear 110 Power Filter · first with an Amazon link

500 gph flow rate.
Priming method: Manual.

Before ordering: For your setup, check maximum tank size: 110 gal.

Paid link · we may earn a commissionCheck current price on Amazon →

If you choose Up to 65 gal for maximum tank size, the first option with an Amazon link becomes Fluval U3 Underwater Filter.

20 aquarium filters compared; 6 have a verified Amazon link.

No hands-on testingMethod and sources

The picks

Five options for different needs

Each option suits a different need. Bigger is useful only if it suits your setup.

Highest rank before your choices

Fluval FX6 High Performance Canister Filter

#1 of 20 in the spec comparison. 400 gal maximum tank size · highest of 20 models; 925 gph flow rate · highest of 20 models.

Why consider it

400 gal maximum tank size.
925 gph flow rate.

Before you choose

For your setup, check maximum tank size: 400 gal.

Buy it ifYou want 400 gal maximum tank size.

Skip it ifYou need a different option for maximum tank size; this model has 400 gal.

Compare it withFluval FX4 High Performance Canister Filter: 250 gal maximum tank size, compared with 400 gal here.

Tank Size Gal Max: 400 galFlow Rate: 925 gphMedia Stages: 4 stages

See all 5 scored specs

Tank Size Gal Max400 gal

Flow Rate925 gph

Media Stages4 stages

Filter TypeCanister

Priming MethodSelf Priming

5 of 5 specs available · specs checked July 2, 2026 · Source ↗

No verified listing yet — check the maker's site for this model.

Compare these models

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First with an Amazon link

Fluval AquaClear 110 Power Filter

#5 of 20 in the spec comparison. 500 gph flow rate · 3rd highest of 20 models; priming method: Manual · 9 of 20 models have this.

Why consider it

500 gph flow rate.
Priming method: Manual.

Before you choose

For your setup, check maximum tank size: 110 gal.

Buy it ifYou want 500 gph flow rate.

Skip it ifYou need a different option for maximum tank size; this model has 110 gal.

Compare it withFluval FX6 High Performance Canister Filter: 400 gal maximum tank size, compared with 110 gal here.

Tank Size Gal Max: 110 galFlow Rate: 500 gphMedia Stages: 3 stages

See all 5 scored specs

Tank Size Gal Max110 gal

Flow Rate500 gph

Media Stages3 stages

Filter TypeHob

Priming MethodManual

5 of 5 specs available · specs checked July 2, 2026 · Source ↗
Amazon listing verified September 4, 2026

Paid link · we may earn a commissionCheck current price on Amazon → Compare

For Up to 65 gal maximum tank size

Fluval 207 Performance Canister Filter

#7 of 20 in the spec comparison. 206 gph flow rate · 11th highest of 20 models; priming method: Self Priming · 6 of 20 models have this.

Why consider it

206 gph flow rate.
Priming method: Self Priming.

Before you choose

For your setup, check maximum tank size: 45 gal.

Buy it ifYou want 206 gph flow rate.

Skip it ifYou need a different option for maximum tank size; this model has 45 gal.

Compare it withFluval FX6 High Performance Canister Filter: 400 gal maximum tank size, compared with 45 gal here.

Tank Size Gal Max: 45 galFlow Rate: 206 gphMedia Stages: 3 stages

See all 5 scored specs

Tank Size Gal Max45 gal

Flow Rate206 gph

Media Stages3 stages

Filter TypeCanister

Priming MethodSelf Priming

5 of 5 specs available · specs checked July 2, 2026 · Source ↗

No verified listing yet — check the maker's site for this model.

Compare these models

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For Up to 3 stages media stages

Fluval 407 Performance Canister Filter

#3 of 20 in the spec comparison. priming method: Self Priming · 6 of 20 models have this; 100 gal maximum tank size · 5th highest of 20 models.

Why consider it

Priming method: Self Priming.
100 gal maximum tank size.

Before you choose

For your setup, check maximum tank size: 100 gal.

Buy it ifYou want Self Priming priming method.

Skip it ifYou need a different option for maximum tank size; this model has 100 gal.

Compare it withFluval FX6 High Performance Canister Filter: 400 gal maximum tank size, compared with 100 gal here.

Tank Size Gal Max: 100 galFlow Rate: 383 gphMedia Stages: 3 stages

See all 5 scored specs

Tank Size Gal Max100 gal

Flow Rate383 gph

Media Stages3 stages

Filter TypeCanister

Priming MethodSelf Priming

5 of 5 specs available · specs checked July 2, 2026 · Source ↗

No verified listing yet — check the maker's site for this model.

Compare these models

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Also compare · Fluval FX4 High Performance Canister Filter

Fluval FX4 High Performance Canister Filter

#2 of 20 in the spec comparison. 250 gal maximum tank size · 2nd highest of 20 models; 4 stages media stages · joint highest of 20 models.

Why consider it

250 gal maximum tank size.
4 stages media stages.

Before you choose

For your setup, check maximum tank size: 250 gal.

Buy it ifYou want 250 gal maximum tank size.

Skip it ifYou need a different option for maximum tank size; this model has 250 gal.

Compare it withFluval FX6 High Performance Canister Filter: 400 gal maximum tank size, compared with 250 gal here.

Tank Size Gal Max: 250 galFlow Rate: 700 gphMedia Stages: 4 stages

See all 5 scored specs

Tank Size Gal Max250 gal

Flow Rate700 gph

Media Stages4 stages

Filter TypeCanister

Priming MethodSelf Priming

5 of 5 specs available · specs checked July 2, 2026 · Source ↗

No verified listing yet — check the maker's site for this model.

Compare these models

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Comparing Fluval AquaClear 110 Power Filter · Fluval FX6 High Performance Canister Filter

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Keep your decision

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The facts that differ

Choose up to three. Facts stay neutral; your choices determine fit.

Differences only

0 identical specs hidden. Non-applicable dimensions are omitted.

Published specification comparison
Spec	Fluval AquaClear 110 Power FilterNo preferences selected.	Fluval FX6 High Performance Canister FilterNo preferences selected.
Tank Size Gal Max	110 gal	400 gal
Flow Rate	500 gph	925 gph
Media Stages	3 stages	4 stages
Filter Type	Hob	Canister
Priming Method	Manual	Self Priming

Fluval AquaClear 110 Power Filter

No preferences selected.

Tank Size Gal Max: 110 gal
Flow Rate: 500 gph
Media Stages: 3 stages
Filter Type: Hob
Priming Method: Manual

Fluval FX6 High Performance Canister Filter

No preferences selected.

Tank Size Gal Max: 400 gal
Flow Rate: 925 gph
Media Stages: 4 stages
Filter Type: Canister
Priming Method: Self Priming

Fluval AquaClear 110 Power Filter

Paid link · we may earn a commissionCheck current price on Amazon →

Fluval FX6 High Performance Canister Filter

No verified listing yet.

All 20 models, with reasons

— = no verified listing yet. The published order is independent of links.

All models and their decision specs
#	Product	Why it’s here	Decision specs	Compare	Action
1	Fluval FX6 High Performance Canister Filter	150 gal more maximum tank size · 225 gph more flow rate vs #2.	Tank Size Gal Max: 400 galFlow Rate: 925 gphMedia Stages: 4 stages	Compare	—
2	Fluval FX4 High Performance Canister Filter	150 gal more maximum tank size · 317 gph more flow rate vs #3.	Tank Size Gal Max: 250 galFlow Rate: 700 gphMedia Stages: 4 stages	Compare	—
3	Fluval 407 Performance Canister Filter	119 gph more flow rate vs #4.	Tank Size Gal Max: 100 galFlow Rate: 383 gphMedia Stages: 3 stages	Compare	—
4	Eheim Classic 600 External Canister Filter	49 gal more maximum tank size vs #5.	Tank Size Gal Max: 159 galFlow Rate: 264 gphMedia Stages: 3 stages	Compare	—
5	Fluval AquaClear 110 Power Filter	40 gal more maximum tank size · 197 gph more flow rate vs #6.	Tank Size Gal Max: 110 galFlow Rate: 500 gphMedia Stages: 3 stages	Compare	Paid link · we may earn a commissionCheck current price on Amazon →
6	Fluval 307 Performance Canister Filter	25 gal more maximum tank size · 97 gph more flow rate vs #7.	Tank Size Gal Max: 70 galFlow Rate: 303 gphMedia Stages: 3 stages	Compare	Paid link · we may earn a commissionCheck current price on Amazon →
7	Fluval 207 Performance Canister Filter	#7 of 20 in the spec comparison. 206 gph flow rate · 11th highest of 20 models; priming method: Self Priming · 6 of 20 models have this.	Tank Size Gal Max: 45 galFlow Rate: 206 gphMedia Stages: 3 stages	Compare	—
8	Marineland Penguin PRO 375 Power Filter	211 gph more flow rate vs #9.	Tank Size Gal Max: 75 galFlow Rate: 375 gphMedia Stages: 3 stages	Compare	—
9	Eheim Classic 350 External Canister Filter	62 gal more maximum tank size · 19 gph more flow rate vs #10.	Tank Size Gal Max: 92 galFlow Rate: 164 gphMedia Stages: 3 stages	Compare	—
10	Fluval 107 Performance Canister Filter	#10 of 20 in the spec comparison. 145 gph flow rate · 15th highest of 20 models; priming method: Self Priming · 6 of 20 models have this.	Tank Size Gal Max: 30 galFlow Rate: 145 gphMedia Stages: 3 stages	Compare	—
11	Fluval AquaClear 70 Power Filter	20 gal more maximum tank size · 25 gph more flow rate vs #12.	Tank Size Gal Max: 70 galFlow Rate: 300 gphMedia Stages: 3 stages	Compare	Paid link · we may earn a commissionCheck current price on Amazon →
12	Marineland Penguin PRO 275 Power Filter	159 gph more flow rate vs #13.	Tank Size Gal Max: 50 galFlow Rate: 275 gphMedia Stages: 3 stages	Compare	—
13	Eheim Classic 250 External Canister Filter	16 gal more maximum tank size vs #14.	Tank Size Gal Max: 66 galFlow Rate: 116 gphMedia Stages: 3 stages	Compare	Paid link · we may earn a commissionCheck current price on Amazon →
14	Fluval AquaClear 50 Power Filter	#14 of 20 in the spec comparison. filter type: Hob · 7 of 20 models have this; 200 gph flow rate · 12th highest of 20 models.	Tank Size Gal Max: 50 galFlow Rate: 200 gphMedia Stages: 3 stages	Compare	—
15	Fluval U4 Underwater Filter	45 gal more maximum tank size · 135 gph more flow rate vs #16.	Tank Size Gal Max: 65 galFlow Rate: 260 gphMedia Stages: 3 stages	Compare	—
16	Marineland Penguin PRO 125 Power Filter	25 gph more flow rate vs #17.	Tank Size Gal Max: 20 galFlow Rate: 125 gphMedia Stages: 3 stages	Compare	—
17	Fluval AquaClear 20 Power Filter	#17 of 20 in the spec comparison. filter type: Hob · 7 of 20 models have this; 100 gph flow rate · 19th highest of 20 models.	Tank Size Gal Max: 20 galFlow Rate: 100 gphMedia Stages: 3 stages	Compare	—
18	Fluval U3 Underwater Filter	10 gal more maximum tank size · 45 gph more flow rate vs #19.	Tank Size Gal Max: 40 galFlow Rate: 155 gphMedia Stages: 3 stages	Compare	Paid link · we may earn a commissionCheck current price on Amazon →
19	Fluval U2 Underwater Filter	15 gal more maximum tank size · 45 gph more flow rate vs #20.	Tank Size Gal Max: 30 galFlow Rate: 110 gphMedia Stages: 3 stages	Compare	—
20	Fluval U1 Underwater Filter	#20 of 20 in the spec comparison. 15 gal maximum tank size · 20th highest of 20 models; 65 gph flow rate · 20th highest of 20 models.	Tank Size Gal Max: 15 galFlow Rate: 65 gphMedia Stages: 2 stages	Compare	Paid link · we may earn a commissionCheck current price on Amazon →

#1 Fluval FX6 High Performance Canister Filter

150 gal more maximum tank size · 225 gph more flow rate vs #2.

Tank Size Gal Max: 400 galFlow Rate: 925 gphMedia Stages: 4 stages

Compare—

#2 Fluval FX4 High Performance Canister Filter

150 gal more maximum tank size · 317 gph more flow rate vs #3.

Tank Size Gal Max: 250 galFlow Rate: 700 gphMedia Stages: 4 stages

Compare—

#3 Fluval 407 Performance Canister Filter

119 gph more flow rate vs #4.

Tank Size Gal Max: 100 galFlow Rate: 383 gphMedia Stages: 3 stages

Compare—

#4 Eheim Classic 600 External Canister Filter

49 gal more maximum tank size vs #5.

Tank Size Gal Max: 159 galFlow Rate: 264 gphMedia Stages: 3 stages

Compare—

#5 Fluval AquaClear 110 Power Filter

40 gal more maximum tank size · 197 gph more flow rate vs #6.

Tank Size Gal Max: 110 galFlow Rate: 500 gphMedia Stages: 3 stages

ComparePaid link · we may earn a commissionCheck current price on Amazon →

#6 Fluval 307 Performance Canister Filter

25 gal more maximum tank size · 97 gph more flow rate vs #7.

Tank Size Gal Max: 70 galFlow Rate: 303 gphMedia Stages: 3 stages

ComparePaid link · we may earn a commissionCheck current price on Amazon →

#7 Fluval 207 Performance Canister Filter

#7 of 20 in the spec comparison. 206 gph flow rate · 11th highest of 20 models; priming method: Self Priming · 6 of 20 models have this.

Tank Size Gal Max: 45 galFlow Rate: 206 gphMedia Stages: 3 stages

Compare—

20 matching models

How we rank and where the facts come from

We compare published specifications, not hands-on experience. Requirements filter the set; the sealed published order is unchanged. The index uses fixed weights and gives missing specs a midpoint. That is an assumption, not evidence of fit or quality. Unknown details cannot qualify a match.

What changed: specs in this snapshot were checked July 2, 2026; listing identities were checked separately through September 4, 2026. This package includes no prior spec revision; changes to individual values cannot be established.

Full methodology Report a correction

Sources for all 20 models

Fluval FX6 High Performance Canister Filter: Fluval ↗ · July 1, 2026
Fluval FX4 High Performance Canister Filter: Fluval ↗ · July 1, 2026
Fluval 407 Performance Canister Filter: Fluval ↗ · July 1, 2026
Eheim Classic 600 External Canister Filter: Eheim ↗ · July 2, 2026
Fluval AquaClear 110 Power Filter: Fluval ↗ · July 1, 2026
Fluval 307 Performance Canister Filter: Fluval ↗ · July 1, 2026
Fluval 207 Performance Canister Filter: Fluval ↗ · July 1, 2026
Marineland Penguin PRO 375 Power Filter: Marineland ↗ · July 1, 2026
Eheim Classic 350 External Canister Filter: Eheim ↗ · July 1, 2026
Fluval 107 Performance Canister Filter: Fluval ↗ · July 1, 2026
Fluval AquaClear 70 Power Filter: Fluval ↗ · July 1, 2026
Marineland Penguin PRO 275 Power Filter: Marineland ↗ · July 1, 2026
Eheim Classic 250 External Canister Filter: Eheim ↗ · July 1, 2026
Fluval AquaClear 50 Power Filter: Fluval ↗ · July 1, 2026
Fluval U4 Underwater Filter: Fluval Aquatics ↗ · July 2, 2026
Marineland Penguin PRO 125 Power Filter: Marineland ↗ · July 1, 2026
Fluval AquaClear 20 Power Filter: Fluval ↗ · July 1, 2026
Fluval U3 Underwater Filter: Fluval Aquatics ↗ · July 2, 2026
Fluval U2 Underwater Filter: Fluval Aquatics ↗ · July 2, 2026
Fluval U1 Underwater Filter: Fluval Aquatics ↗ · July 2, 2026

Show the index and published weights

Weights: Tank Size Gal Max 27% · Flow Rate 24% · Media Stages 21% · Filter Type 19% · Priming Method 9%.

Fluval FX6 High Performance Canister Filter: 100/100
Fluval FX4 High Performance Canister Filter: 83/100
Fluval 407 Performance Canister Filter: 53/100
Eheim Classic 600 External Canister Filter: 50/100
Fluval AquaClear 110 Power Filter: 50/100
Fluval 307 Performance Canister Filter: 49/100
Fluval 207 Performance Canister Filter: 45/100
Marineland Penguin PRO 375 Power Filter: 44/100
Eheim Classic 350 External Canister Filter: 43/100
Fluval 107 Performance Canister Filter: 42/100
Fluval AquaClear 70 Power Filter: 42/100
Marineland Penguin PRO 275 Power Filter: 40/100
Eheim Classic 250 External Canister Filter: 40/100
Fluval AquaClear 50 Power Filter: 38/100
Fluval U4 Underwater Filter: 37/100
Marineland Penguin PRO 125 Power Filter: 33/100
Fluval AquaClear 20 Power Filter: 33/100
Fluval U3 Underwater Filter: 32/100
Fluval U2 Underwater Filter: 30/100
Fluval U1 Underwater Filter: 17/100

Before you buy

Why do some picks have no buy link?

Only exact models with verified Amazon listings receive links. Other models keep their place. A link does not establish current stock or price.

Does the highest rank mean the right product for me?

Start with your requirements, then compare the recorded differences. The published order reflects one set of weights, which may differ from your priorities.

What should I confirm before ordering?

Check the exact model, compatibility, current price and return terms. Published specs do not establish reliability, noise, comfort or ownership experience.