Is fish tank filter cartridge profitable to sell on Amazon United States?

The niche generates $189K/yr across 50 tracked products. 1 of 6 products launched in the last 360 days are still selling. 90-day search growth is -2.7%. Flapen's verdict: Worth a look (55/100).

How competitive is the fish tank filter cartridge niche?

25 brands and 94 sellers compete. The top 5 products take 40% of clicks and top 5 brands hold 70% of demand.

What do buyers complain about in fish tank filter cartridge?

Top complaints mined from reviews: Durability, Filtration, Size-Overall. The return rate is 1.8%.

When does demand for fish tank filter cartridge peak?

Demand peaks in Sep–Oct–Nov; the busiest month runs 3.7× the quietest.

What does it cost to enter the fish tank filter cartridge niche?

Listings span $6.37–$33.92; the average listing price is $12.92 (sweet spot $15–$100). The average incumbent carries 6,267 reviews — the moat a new listing must climb.

fish tank filter cartridge

Worth a look

Shows low returns (1.8%), but soft demand (-2.7% this quarter) keeps it on the watch list.

Returns

Great1.8%

return rate — above 6% kills the launch gate

Competition

Great40%

top-5 click share — an open shelf

Price range

Good$6.37–$33.92

cheapest to priciest tracked listing — scored on the share inside $15–$100

Conversion

Good6.2%

search→purchase rate — share of searches ending in a sale

Quality gap

Good4.4★

avg incumbent rating — lower means beatable quality

Brand share

Good70%

top-5 brand share — brands hold most of the demand

Avg price

Good$12.92

avg listing price — sweet spot $15–$100

Market size

Okay$189K

$189K/yr · 238K searches

Growth

Bad-2.7%

90-day search growth — must beat 0% to launch

Review moat

Bad6,267.2

avg incumbent reviews — the moat a new listing must climb

According to Flapen's Amazon United States niche tracking, fish tank filter cartridge is a $189K/yr Amazon United States market (238K searches/yr). The top 5 brands hold 70% of demand. Demand peaks in Sep–Oct–Nov. Verdict: Worth a look — 55/100.

Data updated Jul 17, 2026 · scored weekly · How we score niches

fish tank filter cartridge market data

Units sold / yr: 15K–20K; avg 250–500/product
Revenue / yr: $194K–$258K; units × avg price
Launch success: 17%; 1 of 6 new (360d)
Conversion rate: 6.2%
Avg BSR: #54
Page quality: 0%
Prime: 100%
Sponsored: 72%
Out of stock: 0.7%
Avg brand age: 53 months
Avg seller age: 141 days

Competition & brand share

Clicks spread well past the top 5 (40% combined) — an open shelf where new products get seen.

Brands

25 flat

Sellers

Top-5 brand share

70%

Top 20: 97%

Top-5 click share

40%

Top 20: 75%

Open market

24%

Tetra37%
NICREW10%
Aqueon8%
HiTauing8%
Zuqqony7%
DaToo6%

Demand & seasonality

Weekly Amazon search volume, last 104 weeks — -2.7% search growth over the last 90 days.

Peak months: Sep, Oct, Nov · busiest ÷ quietest = 3.7×

Open Trend

Top fish tank filter cartridge search terms

aquarium filter cartridge22K/yr -2.9%3.2% conv.
filter cartridge17K/yr +53.4%0.5% conv.
betta fish filter18K/yr +3.3%3.4% conv.
fish tank filter cartridge21K/yr -13.1%4.2% conv.
small tank filter17K/yr -4.9%3.9% conv.
betta tank filter14K/yr -4.4%3.3% conv.
beta fish tank filter16K/yr -19.2%4.7% conv.
beta fish filter11K/yr +0.0%5.1% conv.
tetra whisper filter medium7K/yr +56.4%14.6% conv.
filter cartridge fish tank12K/yr -11.0%3.9% conv.

All search terms

Top fish tank filter cartridge products on Amazon

Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.

Beatable (≤4.3★) Contested Strong incumbent (>4.7★)

All 50 tracked products in this niche — three views at once, no toggling.

Top sellers

by 90-day click share

Tetra Whisper Bio-Bag Medium Filter Cartridges for Aquariums 3 Count Ready to Use Fits Tetra Whisper Fish Tank Filters 5-10 Gal PF-10 IQ 10

Tetra$6.374.7★28,155 rev

Tetra Whisper 4i Internal Power Filter Filtration for Aquariums Between 1 and 4 Gallons

Tetra$12.354.3★22,392 rev

NICREW Slim Aquarium Filter Quiet Fish Tank HOB Filters for up to 5 Gallon Aquariums Adjustable Flow 42 GPH 3W

NICREW$12.344.1★2,763 rev

HiTauing 8 Pack EF-S Filter Cartridges for EF-S Element and BF5 BETTAFLO

HiTauing$8.694.6★3,205 rev

DaToo Aquarium Power Filter In-Tank Ultra Silent Small Fish Tank Filter 3W For Aquarium 1 to 10 Gallon Tank 1 Yr Warranty

DaToo$7.754.0★3,198 rev

Newest

by launch date

ziqniot 6pcs EF-S Filter Cartridge Compatible EF-S Element/BF5 BETTAFLO 3.76x1.97 inch

ziqniot$6.4049 rev

1mo ago

Carefree Fish Aquarium Small Sponge Bubble Filter with Fish Poops Collector Quiet for 3~8Gal Fish Tank for Saltwater and Freshwater(Not Include Air Pump)

Carefree Fish$9.8230 rev

3mo ago

12-Pack EF-S Replacement Filter Cartridges for BF5 BettaFlo Aquarium Professional Triple Filtration to Keep Water Crystal Clear & Fish Healthy High-Density Activated Carbon Refills for Fish Tank

Meidier$7.2475 rev

5mo ago

Chyodi 16 Pack Medium Filter Cartridges Compatible with Tetra Whisper Bio-Bag Filters Medium for Whisper 10i/IQ10/PF10 and Repto Filter 90 GPH for Medium Aquarium Filter Cartridge

Chyodi$22.25130 rev

8mo ago

QiQiWader Small Aquarium Filter Fish Tank Filter Suitable for 3-10 Gallon Fish Tanks 3W 80GPH with Two Modes Switching Function.

QiQiWader$16.8098 rev

9mo ago

What buyers say about fish tank filter cartridge

What buyers praise and complain about, mined from review topics.

What buyers love

Filtration28%

“Excellent filters”

Value For Money12%

“Very affordable”

Size-Overall12%

“sizing is accurate”

Quality-Overall10%

“Excellent product”

Advertised Vs Actual Product7%

“As advertised”

Ease Of Cleaning6%

“It cleans well”

Ease Of Use3%

“Easy as pie”

Water Flow3%

“so quiet water flow is great”

Durability2%

“Durability is great as well”

Spray/Flow2%

“Allows the water to flow through”

What buyers complain about

Durability20%

“Breaks easily”

Filtration16%

“Does not filter good”

Size-Overall10%

“they don't fit”

Quality-Overall7%

“I thought the quality would be off due to them not being name brand”

Functionality-Overall6%

“Not effective”

Leak-Proof3%

“It leaks”

Ease Of Cleaning3%

“is not easy to clean”

Water Flow3%

“The water flow is extremely weak”

Value For Money2%

“Price a little high, for filters”

Assembly/Installation2%

“Sadly, this is difficult to assemble”

Top return reasons

Size-Overall67%

Filtration15%

Functionality-Overall4%

Advertised Vs Actual Product3%

Compatibility-Overall3%

Defective Material/Parts2%

Value For Money1%

Durability1%

Product Condition1%

Assembly/Installation0%

Common questions

Is fish tank filter cartridge profitable to sell on Amazon United States?: The niche generates $189K/yr across 50 tracked products. 1 of 6 products launched in the last 360 days are still selling. 90-day search growth is -2.7%. Flapen's verdict: Worth a look (55/100).
How competitive is the fish tank filter cartridge niche?: 25 brands and 94 sellers compete. The top 5 products take 40% of clicks and top 5 brands hold 70% of demand.
What do buyers complain about in fish tank filter cartridge?: Top complaints mined from reviews: Durability, Filtration, Size-Overall. The return rate is 1.8%.
When does demand for fish tank filter cartridge peak?: Demand peaks in Sep–Oct–Nov; the busiest month runs 3.7× the quietest.
What does it cost to enter the fish tank filter cartridge niche?: Listings span $6.37–$33.92; the average listing price is $12.92 (sweet spot $15–$100). The average incumbent carries 6,267 reviews — the moat a new listing must climb.