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.

methylene blue for fish

Skip it

Soft demand (-19.9% this quarter) — this niche doesn't clear our bar today.

Returns

Great1.0%

return rate — above 6% kills the launch gate

Conversion

Great10.9%

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

Quality gap

Okay4.5★

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

Bad4,525.45

avg incumbent reviews — the moat a new listing must climb

Market size

Bad$84K

$84K/yr · 73K searches

Competition

Bad76%

top-5 click share — a locked-up shelf

Brand share

Bad92%

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

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

Top-5 brand share

92%

Top 20: 100%

Top-5 click share

76%

Top 20: 100%

Open market

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.

Peak months: Feb, Mar · busiest ÷ quietest = 1.9×

Open Trend

Top methylene blue for fish search terms

methylene blue for fish47K/yr -18.3%7.4% conv.
azul de metileno para peces8K/yr +26.7%6.7% conv.
methylene blue aquarium7K/yr -35.9%7.5% conv.
methylene blue fish7K/yr -33.4%7.3% conv.
methylene blue for fish aquarium5K/yr -39.6%5.9% conv.

All 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.

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

Kordon Methylene Blue Disease Preventative Safe for Freshwater & Saltwater Aquariums Prevents Fungal Infections & Treats Parasites Reduces Fish Stress 4-Ounces

Kordon$7.864.7★3,775 rev

API MELAFIX Freshwater Fish Bacterial Infection Remedy 16-Ounce Bottle

API$14.154.5★15,244 rev

ALDON Innovating Science Methylene Blue 1% Aqueous Solution 1 fl oz (30mL) Dropper Bottle - Methyl Blue Microscope Stain - The Curated Chemical Collection

ALDON$9.884.5★814 rev

Aquaetic Methylene Blue- 8 Ounce Bottle

Dawn Scientific$18.844.6★101 rev

API LIQUID SUPER ICK CURE Fish remedy Freshwater and Saltwater Fish Medication 4 fl oz(Pack of 1) White

API$7.234.5★11,785 rev

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$8.305 rev

7mo ago

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$13.0869 rev

9mo ago

Aquaetic Methylene Blue- 8 Ounce Bottle

Dawn Scientific$18.84101 rev

5y ago

ALDON Innovating Science Methylene Blue 1% Aqueous Solution 1 fl oz (30mL) Dropper Bottle - Methyl Blue Microscope Stain - The Curated Chemical Collection

ALDON$9.88814 rev

7y ago

API MELAFIX Freshwater Fish Bacterial Infection Remedy 16-Ounce Bottle

API$14.1515,244 rev

22y ago

What buyers say about methylene blue for fish

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

What buyers love

Quality-Overall23%

“Seems good quality”

Value For Money18%

“Good price”

Ease Of Use12%

“Easy to Use”

Advertised Vs Actual Product7%

“Gets the job done”

Color5%

“Its very pretty”

Smell5%

“I love the smell”

Instructions/User Manual/Troubleshooting5%

“the instructions were clear”

Time Taken4%

“Helped quickly”

Taste-Overall4%

“my water tastes very well I recommended to save money”

Size-Overall3%

“So the size is good”

What buyers complain about

Durability16%

“died very quickly after that”

Color13%

“His color faded”

Instructions/User Manual/Troubleshooting8%

“HORRIBLE, DID AS INSTRUCTED, and it did nothing”

Breathability8%

“from not being able to breath”

Value For Money7%

“Which cost me a lot of money”

Contamination7%

“Caused fish d**th”

Water Flow6%

“Be careful using this also increase the water bubbles the water alot”

Functionality-Overall5%

“Did not do anything to help. Done nothing”

Indigestion4%

“Poison product”

Size-Overall3%

“It is small”

Top return reasons

Functionality-Overall35%

Leak-Proof18%

Value For Money12%

Advertised Vs Actual Product11%

Size-Overall5%

Compatibility-Overall3%

Defective Material/Parts3%

Durability2%

Certifications2%

Moist/Dry2%

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.