overflow box
Skip itWeak search conversion (0.4%) — this niche doesn't clear our bar today.
Quality gap
Incredible4.0★avg incumbent rating — lower means beatable quality
Review moat
Great103.14avg incumbent reviews — the moat a new listing must climb
Avg price
Good$120.03avg listing price — sweet spot $15–$100
Competition
Good48%top-5 click share — leaders hold, buyers still browse
Brand share
Okay79%top-5 brand share — brands hold most of the demand
Price range
Okay$15.77–$205.58cheapest to priciest tracked listing — scored on the share inside $15–$100
Returns
Bad7.1%return rate — above 6% kills the launch gate
Growth
Bad-14.4%90-day search growth — must beat 0% to launch
Market size
Bad$35K$35K/yr · 65K searches
Conversion
Bad0.4%search→purchase rate — share of searches ending in a sale
According to Flapen's Amazon United States niche tracking, overflow box is a $35K/yr Amazon United States market (65K searches/yr). The top 5 brands hold 79% of demand. Verdict: Skip it — 40/100.
Data updated Jul 17, 2026 · scored weekly · How we score niches
overflow box market data
- Units sold / yr
- 250–500
- avg 0–100/product
- Revenue / yr
- $30K–$60K
- units × avg price
- Launch success
- —
- 0 of 1 new (360d)
- Conversion rate
- 0.4%
- Avg BSR
- #1,801
- Page quality
- 0%
- Prime
- 81%
- Sponsored
- 48%
- Out of stock
- 20.8%
- Avg brand age
- 55 months
- Avg seller age
- 182 days
Competition & brand share
The top 5 products take 48% of clicks — established leaders, but buyers still shop beyond them.Brands
12 falling
Sellers
35
Top-5 brand share
79%
Top 20: 100%
Top-5 click share
48%
Top 20: 99%
Open market
15%
- ESHOPPS34%
- Seapora17%
- Fiji Cube10%
- XJHHZHBH9%
- Aqueon9%
- Blue Ocean7%
- Open — no brand owns it (6 brands, 15%)
Demand
Weekly Amazon search volume, last 28 weeks — -14.4% search growth over the last 90 days.Top overflow box search terms
- overflow box20K/yr
- aquarium overflow box16K/yr
- aquarium overflow kit9K/yr
- aquarium overflow8K/yr
- overflow box for aquarium sump7K/yr
- eshopps overflow box4K/yr
Top overflow box 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.
All 21 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Seapora Nano Overflow Box Black
Seapora$56.104.0★88 rev
Eshopps AEO11010 Overflow Boxes Pf-1000 for Aquarium Tanks
ESHOPPS$149.483.9★64 rev
XJHHZHBH Ultra Slim Aquarium Overflow Box for Rimless Tanks No-Drill Silent U-Tube Siphon Dual Inlet Skimmer for Waste & Oil Film 5000 L/H High Flow Fits 1218 inch Aquariums
XJHHZHBH$90.532.5★3 rev
Aqueon AAG29251 Overflow Accessory New Kit
Aqueon$74.894.5★290 rev
Blue Ocean of 600 Overflow Box Continuous Siphon 125G Aquarium
Blue Ocean$94.414.3★186 rev
Newest
by launch dateXJHHZHBH Ultra Slim Aquarium Overflow Box for Rimless Tanks No-Drill Silent U-Tube Siphon Dual Inlet Skimmer for Waste & Oil Film 5000 L/H High Flow Fits 1218 inch Aquariums
XJHHZHBH$90.533 rev
Overflow Box for Aquariums Overflow Pre Filter Quality Acrylic Self Start Siphon Hang On Overflow Box for Fish Aquarium
SASKATE$131.654 rev
Acrylic Self Start Siphon Hang On Overflow Box High Light Transmittance Prevents Debris Movable Outlet Cover Check Valve Fish Aquarium
Keenso$112.813 rev
Quality Acrylic Self Start Siphon Hang On Overflow Box Super Quiet for Fish Tank Aquarium
EVTSCAN$123.737 rev
Eshopps 62695858: Overflow Box Prodigy L
ESHOPPS$205.583 rev
Trending
90-day click momentum
Seapora 56097 Overflow Pre-Filter
Seapora$100.743.6★
Eshopps 62695858: Overflow Box Prodigy L
ESHOPPS$205.585.0★
Fiji Cube Low Profile External Overflow Box (800 GPH)
Fiji Cube$158.294.4★
Fiji Cube Low Profile External Overflow Box (1200 GPH)
Fiji Cube$172.803.9★
XJHHZHBH Ultra Slim Aquarium Overflow Box for Rimless Tanks No-Drill Silent U-Tube Siphon Dual Inlet Skimmer for Waste & Oil Film 5000 L/H High Flow Fits 1218 inch Aquariums
XJHHZHBH$90.532.5★
What buyers say about overflow box
What buyers praise and complain about, mined from review topics.What buyers love
“Great deal”
“quality item,”
“Seems well built”
“good product very slim”
“I've used them for years”
“Wonderful life support system for my fish”
“they barley fit in it”
“Super easy and fast to install”
“Super easy and works”
What buyers complain about
“Both bulkheads leak”
“couldn't get the water level correct”
“One was off in size”
“The description is very undetailed”
“Had it for 2 months”
“cheap fixes if the product is good”
“It is quite over-priced for what you get”
“The install is way too low in the tank”
“This causes the water level to be too low inside the internal box”
“It's not very well designed though”
Top return reasons
Common questions
- Is overflow box profitable to sell on Amazon United States?
- The niche generates $35K/yr across 21 tracked products. 0 of 1 products launched in the last 360 days are still selling. 90-day search growth is -14.4%. Flapen's verdict: Skip it (40/100).
- How competitive is the overflow box niche?
- 12 brands and 35 sellers compete. The top 5 products take 48% of clicks and top 5 brands hold 79% of demand.
- What do buyers complain about in overflow box?
- Top complaints mined from reviews: Leak-Proof, Water Resistance, Size-Overall. The return rate is 7.1% — above our launch gate.
- What does it cost to enter the overflow box niche?
- Listings span $15.77–$205.58; the average listing price is $120.03 (sweet spot $15–$100). The average incumbent carries 103 reviews — the moat a new listing must climb.