---
title: "Overflow Box — $35K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/pet-supplies/overflow-box"
last_updated: "2026-07-21T17:35:58.703Z"
locale: en
meta:
description: "Niche score 40/100 · $35K/yr market · 65K searches/yr · $120.03 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 40/100 · $35K/yr market · 65K searches/yr · $120.03 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Overflow Box — $35K/yr Amazon US Niche (2026) - Flapen"
---
# **overflow box**
**Skip it**
Weak search conversion (0.4%) — this niche doesn't clear our bar today.
Market size 9Growth 18Conversion 6Competition 61Returns 20Price range 44Avg price 68Brand share 44Review moat 95Quality gap 95
**Quality gap**
**Incredible****4.0★**
avg incumbent rating — lower means beatable quality
**Review moat**
**Great****103.14**
avg incumbent reviews — the moat a new listing must climb
**Avg price**
**Good****$120.03**
avg listing price — sweet spot $15–$100
**Competition**
**Good****48%**
top-5 click share — leaders hold, buyers still browse
**Brand share**
**Okay****79%**
top-5 brand share — brands hold most of the demand
**Price range**
**Okay****$15.77–$205.58**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Returns**
**Bad****7.1%**
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**
**Bad****0.4%**
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 ~~](https://flapen.com/research/methodology)
## **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.
2K1KJan '26Feb '26Mar '26Mar '26Apr '26May '26Jun '26
[**Open Trend **](https://flapen.com/research/us/pet-supplies/overflow-box/trend)
## **Top overflow box search terms**
- **overflow box**20K/yr-10.0%0.3% conv. - **aquarium overflow box**16K/yr-14.6%0.4% conv. - **aquarium overflow kit**9K/yr-17.7%0.4% conv. - **aquarium overflow**8K/yr-17.3%0.3% conv. - **overflow box for aquarium sump**7K/yr-21.2%0.4% conv. - **eshopps overflow box**4K/yr-12.3%0.7% conv. [**All search terms **](https://flapen.com/research/us/pet-supplies/overflow-box/search-terms)
## **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.
0%4%$1K8%$3K12%$4K16%$6K1101001K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 21 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Seapora Nano Overflow Box Black**Seapora**$56.10**4.0★88 rev](https://www.amazon.com/dp/B0765BK72W) [2**Eshopps AEO11010 Overflow Boxes Pf-1000 for Aquarium Tanks**ESHOPPS**$149.48**3.9★64 rev](https://www.amazon.com/dp/B001K5K8TW) [3**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**$90.53**2.5★3 rev](https://www.amazon.com/dp/B0FT1J9S6X) [4**Aqueon AAG29251 Overflow Accessory New Kit**Aqueon**$74.89**4.5★290 rev](https://www.amazon.com/dp/B0002DJAZQ) [5**Blue Ocean of 600 Overflow Box Continuous Siphon 125G Aquarium**Blue Ocean**$94.41**4.3★186 rev](https://www.amazon.com/dp/B073ZJWQJP)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**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**$90.53**3 rev9mo ago](https://www.amazon.com/dp/B0FT1J9S6X) [**Overflow Box for Aquariums Overflow Pre Filter Quality Acrylic Self Start Siphon Hang On Overflow Box for Fish Aquarium**SASKATE**$131.65**4 rev2y ago](https://www.amazon.com/dp/B0D7CT5DHH) [**Acrylic Self Start Siphon Hang On Overflow Box High Light Transmittance Prevents Debris Movable Outlet Cover Check Valve Fish Aquarium**Keenso**$112.81**3 rev2y ago](https://www.amazon.com/dp/B0CTN4YWWX) [**Quality Acrylic Self Start Siphon Hang On Overflow Box Super Quiet for Fish Tank Aquarium**EVTSCAN**$123.73**7 rev5y ago](https://www.amazon.com/dp/B093KNRY31) [**Eshopps 62695858: Overflow Box Prodigy L**ESHOPPS**$205.58**3 rev6y ago](https://www.amazon.com/dp/B083F877DH)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Seapora 56097 Overflow Pre-Filter**Seapora**$100.74**3.6★**▲ 164%**](https://www.amazon.com/dp/B07659MBC7) [**Eshopps 62695858: Overflow Box Prodigy L**ESHOPPS**$205.58**5.0★**▲ 139%**](https://www.amazon.com/dp/B083F877DH) [**Fiji Cube Low Profile External Overflow Box (800 GPH)**Fiji Cube**$158.29**4.4★**▲ 61%**](https://www.amazon.com/dp/B07TTYH7FH) [**Fiji Cube Low Profile External Overflow Box (1200 GPH)**Fiji Cube**$172.80**3.9★**▲ 47%**](https://www.amazon.com/dp/B07TX2SKMX) [**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**$90.53**2.5★**▲ 33%**](https://www.amazon.com/dp/B0FT1J9S6X)
**~~View all trending →~~**
## **What buyers say about overflow box**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Value For Money**29%
*“Great deal”*
**Quality-Overall**14%
*“quality item,”*
**Design-Overall**7%
*“Seems well built”*
**Thickness**7%
*“good product very slim”*
**Durability**7%
*“I've used them for years”*
**Pet Friendly**7%
*“Wonderful life support system for my fish”*
**Size-Overall**4%
*“they barley fit in it”*
**Assembly/Installation**4%
*“Super easy and fast to install”*
**Ease Of Use**4%
*“Super easy and works”*
### **What buyers complain about **
**Leak-Proof**22%
*“Both bulkheads leak”*
**Water Resistance**14%
*“couldn't get the water level correct”*
**Size-Overall**11%
*“One was off in size”*
**Advertised Vs Actual Product**11%
*“The description is very undetailed”*
**Durability**6%
*“Had it for 2 months”*
**Quality-Overall**6%
*“cheap fixes if the product is good”*
**Value For Money**3%
*“It is quite over-priced for what you get”*
**Assembly/Installation**3%
*“The install is way too low in the tank”*
**Water Flow**3%
*“This causes the water level to be too low inside the internal box”*
**Design-Overall**3%
*“It's not very well designed though”*
### **Top return reasons **
**Size-Overall**49%
**Defective Material/Parts**19%
**Compatibility-Overall**7%
**Functionality-Overall**5%
**Advertised Vs Actual Product**4%
**Value For Money**3%
**Leak-Proof**3%
**Material Quality**3%
**Water Flow**2%
**Connectivity-Overall**1%
## **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.
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