---
title: "Methylene Blue for Fish — $84K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/pet-supplies/methylene-blue-for-fish"
last_updated: "2026-07-22T21:30:26.915Z"
locale: en
meta:
description: "Niche score 38/100 · $84K/yr market · 73K searches/yr · $10.52 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 38/100 · $84K/yr market · 73K searches/yr · $10.52 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Methylene Blue for Fish — $84K/yr Amazon US Niche (2026) - Flapen"
---
# **methylene blue for fish**
**Skip it**
Soft demand (-19.9% this quarter) — this niche doesn't clear our bar today.
Market size 21Growth 15Conversion 91Competition 20Returns 95Price range 27Avg price 38Brand share 19Review moat 25Quality gap 47
**Returns**
**Great****1.0%**
return rate — above 6% kills the launch gate
**Conversion**
**Great****10.9%**
search→purchase rate — share of searches ending in a sale
**Quality gap**
**Okay****4.5★**
avg incumbent rating — lower means beatable quality
**Avg price**
**Okay****$10.52**
avg listing price — sweet spot $15–$100
**Price range**
**Okay****$4.53–$18.84**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Review moat**
**Bad****4,525.45**
avg incumbent reviews — the moat a new listing must climb
**Market size**
**Bad****$84K**
$84K/yr · 73K searches
**Competition**
**Bad****76%**
top-5 click share — a locked-up shelf
**Brand share**
**Bad****92%**
top-5 brand share — brand-locked demand
**Growth**
**Bad****-19.9%**
90-day search growth — must beat 0% to launch
According to Flapen's Amazon United States niche tracking, methylene blue for fish is a $84K/yr Amazon United States market (73K searches/yr). The top 5 brands hold 92% of demand. Demand peaks in Feb–Mar. Verdict: Skip it — 38/100.
Data updated Jul 17, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **methylene blue for fish market data**
- **Units sold / yr**
- **6K–8K**
- avg 500–750/product
- **Revenue / yr**
- **$63K–$84K**
- units × avg price
- **Launch success**
- **—**
- 1 of 2 new (360d)
- **Conversion rate**
- **10.9%**
- **Avg BSR**
- **#154**
- **Page quality**
- **0%**
- **Prime**
- **91%**
- **Sponsored**
- **27%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **59 months**
- **Avg seller age**
- **153 days**
## **Competition & brand share**
The top 5 products capture 76% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**7 **▲rising
**Sellers**
**33**
**Top-5 brand share**
**92%**
Top 20: 100%
**Top-5 click share**
**76%**
Top 20: 100%
**Open market**
**4%**
- Kordon45% - API25% - ALDON10% - Dawn Scientific6% - Seachem6% - CAIVOV4% - Open — no brand owns it (1 brand, 4%)
## **Demand & seasonality**
Weekly Amazon search volume, last 101 weeks — -19.9% search growth over the last 90 days.
2K2KHoliday '24Spike '25Spike '26 seasonSepDecMarJunAugNovMarMay
Peak months: Feb, Mar · busiest ÷ quietest = 1.9×
[**Open Trend **](https://flapen.com/research/us/pet-supplies/methylene-blue-for-fish/trend)
## **Top methylene blue for fish search terms**
- **methylene blue for fish**47K/yr-18.3%7.4% conv. - **azul de metileno para peces**8K/yr+26.7%6.7% conv. - **methylene blue aquarium**7K/yr-35.9%7.5% conv. - **methylene blue fish**7K/yr-33.4%7.3% conv. - **methylene blue for fish aquarium**5K/yr-39.6%5.9% conv. [**All search terms **](https://flapen.com/research/us/pet-supplies/methylene-blue-for-fish/search-terms)
## **Top methylene blue for fish 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%15%$13K30%$25K45%$38K60%$51K1101001K10K100K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 11 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Kordon Methylene Blue Disease Preventative Safe for Freshwater & Saltwater Aquariums Prevents Fungal Infections & Treats Parasites Reduces Fish Stress 4-Ounces**Kordon**$7.86**4.7★3,775 rev](https://www.amazon.com/dp/B00025646W) [2**API MELAFIX Freshwater Fish Bacterial Infection Remedy 16-Ounce Bottle**API**$14.15**4.5★15,244 rev](https://www.amazon.com/dp/B0002567T6) [3**ALDON Innovating Science Methylene Blue 1% Aqueous Solution 1 fl oz (30mL) Dropper Bottle - Methyl Blue Microscope Stain - The Curated Chemical Collection**ALDON**$9.88**4.5★814 rev](https://www.amazon.com/dp/B07JMLLJV8) [4**Aquaetic Methylene Blue- 8 Ounce Bottle**Dawn Scientific**$18.84**4.6★101 rev](https://www.amazon.com/dp/B08YWPG3KR) [5**API LIQUID SUPER ICK CURE Fish remedy Freshwater and Saltwater Fish Medication 4 fl oz(Pack of 1) White**API**$7.23**4.5★11,785 rev](https://www.amazon.com/dp/B0002ASG9K)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**Methylene Blue Pharmaceutical Grade 1% USP Grade Methylene Blue Drops Third-Party Tested No Formaldehyde Glass Bottle 20 ML 0.7 FL OZ**CAIVOV**$8.30**5 rev7mo ago](https://www.amazon.com/dp/B0G3KQX25N) [**Core Organo Ultra-Pure & Premium 1% Methylene Blue Drops 3rd Party Lab Tested 99.9% Purity Formaldehyde & Alcohol-Free Pharmaceutical Grade Methylene Blue Drops 60ml (2.02 fl oz)**CORE ORGANO**$13.08**69 rev9mo ago](https://www.amazon.com/dp/B0FRJ24F38) [**Aquaetic Methylene Blue- 8 Ounce Bottle**Dawn Scientific**$18.84**101 rev5y ago](https://www.amazon.com/dp/B08YWPG3KR) [**ALDON Innovating Science Methylene Blue 1% Aqueous Solution 1 fl oz (30mL) Dropper Bottle - Methyl Blue Microscope Stain - The Curated Chemical Collection**ALDON**$9.88**814 rev7y ago](https://www.amazon.com/dp/B07JMLLJV8) [**API MELAFIX Freshwater Fish Bacterial Infection Remedy 16-Ounce Bottle**API**$14.15**15,244 rev22y ago](https://www.amazon.com/dp/B0002567T6)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Core Organo Ultra-Pure & Premium 1% Methylene Blue Drops 3rd Party Lab Tested 99.9% Purity Formaldehyde & Alcohol-Free Pharmaceutical Grade Methylene Blue Drops 60ml (2.02 fl oz)**CORE ORGANO**$13.08**4.2★**▲ 142%**](https://www.amazon.com/dp/B0FRJ24F38) [**Methylene Blue Pharmaceutical Grade 1% USP Grade Methylene Blue Drops Third-Party Tested No Formaldehyde Glass Bottle 20 ML 0.7 FL OZ**CAIVOV**$8.30**4.0★**▲ 58%**](https://www.amazon.com/dp/B0G3KQX25N) [**ALDON Innovating Science Methylene Blue 1% Aqueous Solution 1 fl oz (30mL) Dropper Bottle - Methyl Blue Microscope Stain - The Curated Chemical Collection**ALDON**$9.88**4.5★**▲ 21%**](https://www.amazon.com/dp/B07JMLLJV8) [**API LIQUID SUPER ICK CURE Fish remedy Freshwater and Saltwater Fish Medication 4 fl oz(Pack of 1) White**API**$7.23**4.5★**▲ 19%**](https://www.amazon.com/dp/B0002ASG9K) [**API PIMAFIX Antifungal Freshwater and Saltwater Fish Remedy 16-Ounce Bottle**API**$11.89**4.5★**▲ 12%**](https://www.amazon.com/dp/B000256ESA)
**~~View all trending →~~**
## **What buyers say about methylene blue for fish**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Quality-Overall**23%
*“Seems good quality”*
**Value For Money**18%
*“Good price”*
**Ease Of Use**12%
*“Easy to Use”*
**Advertised Vs Actual Product**7%
*“Gets the job done”*
**Color**5%
*“Its very pretty”*
**Smell**5%
*“I love the smell”*
**Instructions/User Manual/Troubleshooting**5%
*“the instructions were clear”*
**Time Taken**4%
*“Helped quickly”*
**Taste-Overall**4%
*“my water tastes very well I recommended to save money”*
**Size-Overall**3%
*“So the size is good”*
### **What buyers complain about **
**Durability**16%
*“died very quickly after that”*
**Color**13%
*“His color faded”*
**Instructions/User Manual/Troubleshooting**8%
*“HORRIBLE, DID AS INSTRUCTED, and it did nothing”*
**Breathability**8%
*“from not being able to breath”*
**Value For Money**7%
*“Which cost me a lot of money”*
**Contamination**7%
*“Caused fish d**th”*
**Water Flow**6%
*“Be careful using this also increase the water bubbles the water alot”*
**Functionality-Overall**5%
*“Did not do anything to help. Done nothing”*
**Indigestion**4%
*“Poison product”*
**Size-Overall**3%
*“It is small”*
### **Top return reasons **
**Functionality-Overall**35%
**Leak-Proof**18%
**Value For Money**12%
**Advertised Vs Actual Product**11%
**Size-Overall**5%
**Compatibility-Overall**3%
**Defective Material/Parts**3%
**Durability**2%
**Certifications**2%
**Moist/Dry**2%
## **Common questions**
- **Is methylene blue for fish profitable to sell on Amazon United States?**
- The niche generates $84K/yr across 11 tracked products. 1 of 2 products launched in the last 360 days are still selling. 90-day search growth is -19.9%. Flapen's verdict: Skip it (38/100).
- **How competitive is the methylene blue for fish niche?**
- 7 brands and 33 sellers compete. The top 5 products take 76% of clicks and top 5 brands hold 92% of demand.
- **What do buyers complain about in methylene blue for fish?**
- Top complaints mined from reviews: Durability, Color, Instructions/User Manual/Troubleshooting. The return rate is 1.0%.
- **When does demand for methylene blue for fish peak?**
- Demand peaks in Feb–Mar; the busiest month runs 1.9× the quietest.
- **What does it cost to enter the methylene blue for fish niche?**
- Listings span $4.53–$18.84; the average listing price is $10.52 (sweet spot $15–$100). The average incumbent carries 4,525 reviews — the moat a new listing must climb.
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