refractometer saltwater aquarium
Skip itA concentrated shelf (top 5 take 93% of clicks) — this niche doesn't clear our bar today.
Conversion
Great11.1%search→purchase rate — share of searches ending in a sale
Price range
Great$13.37–$48.86cheapest to priciest tracked listing — scored on the share inside $15–$100
Avg price
Great$20.49avg listing price — sweet spot $15–$100
Review moat
Good1,247.86avg incumbent reviews — the moat a new listing must climb
Returns
Good2.9%return rate — above 6% kills the launch gate
Quality gap
Good4.4★avg incumbent rating — lower means beatable quality
Growth
Bad-11.3%90-day search growth — must beat 0% to launch
Brand share
Bad93%top-5 brand share — brand-locked demand
Market size
Bad$54K$54K/yr · 24K searches
Competition
Bad93%top-5 click share — a locked-up shelf
According to Flapen's Amazon United States niche tracking, refractometer saltwater aquarium is a $54K/yr Amazon United States market (24K searches/yr). The top 5 brands hold 93% of demand. Demand peaks in Jan–Aug–Sep. Verdict: Skip it — 39/100.
Data updated Jul 17, 2026 · scored weekly · How we score niches
refractometer saltwater aquarium market data
- Units sold / yr
- 3K–3K
- avg 250–500/product
- Revenue / yr
- $51K–$61K
- units × avg price
- Launch success
- —
- 0 of 0 new (360d)
- Conversion rate
- 11.1%
- Avg BSR
- #23
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 86%
- Out of stock
- 2.6%
- Avg brand age
- 68 months
- Avg seller age
- 186 days
Competition & brand share
The top 5 products capture 93% of clicks — a locked-up shelf that new listings rarely crack.Brands
7 flat
Sellers
10
Top-5 brand share
93%
Top 20: 100%
Top-5 click share
93%
Top 20: 100%
Open market
3%
- Agriculture Solutions60%
- Hallocool15%
- SunGrow8%
- Anbachi7%
- AUTOUTLET4%
- TOOGOND3%
- Open — no brand owns it (1 brand, 3%)
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -11.3% search growth over the last 90 days.Peak months: Jan, Aug, Sep · busiest ÷ quietest = 2.4×
Top refractometer saltwater aquarium 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 7 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Agriculture Solutions Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium 0-100 PPT with Automatic Temperature Compensation
Agriculture Solutions$17.944.6★4,821 rev
Salinity Refractometer for Aquarium Seawater Marine Fishkeeping Salinity Tester 0-100PPT & 1.000-1.070 Salinity Hydrometer Slatwater Refractometer with Automatic Temperature Compensation (ATC)
Hallocool$16.254.5★581 rev
SunGrow Measure Salinity of Water with Aquarium Refractometer Remarkable Accuracy Easy Reading
SunGrow$13.374.5★580 rev
Digital Salinity Meter 3-in-1 Saltwater Tester Specific Gravity Salinity & Temperature Pen Hydrometer High Accuracy Water Quality Tester for Aquarium Marine Pool Hydroponics Aquaculture
Anbachi$48.864.1★91 rev
AUTOUTLET Refractometer Saltwater Aquarium for Seawater Pool Tank Testing Marine Fishkeeping 0-100PPT & 1.000-1.070 Salinity Tester with ATC Function Hydrometer Specific Gravity Salinity Meter Kit
AUTOUTLET$15.994.6★2,349 rev
Newest
by launch date
Professional Salinity Refractometer Salinity Tester Salt Tester for Saltwater Pool for Saltwater Aquarium Pools and Tanks Dual Scale 0-100 PPT & Specific Gravity 1.000-1.070 with ATC Function
TOOGOND$15.7888 rev
Digital Salinity Meter 3-in-1 Saltwater Tester Specific Gravity Salinity & Temperature Pen Hydrometer High Accuracy Water Quality Tester for Aquarium Marine Pool Hydroponics Aquaculture
Anbachi$48.8691 rev
Salinity Refractometer for Aquarium Seawater Marine Fishkeeping Salinity Tester 0-100PPT & 1.000-1.070 Salinity Hydrometer Slatwater Refractometer with Automatic Temperature Compensation (ATC)
Hallocool$16.25581 rev
AUTOUTLET Refractometer Saltwater Aquarium for Seawater Pool Tank Testing Marine Fishkeeping 0-100PPT & 1.000-1.070 Salinity Tester with ATC Function Hydrometer Specific Gravity Salinity Meter Kit
AUTOUTLET$15.992,349 rev
SunGrow Measure Salinity of Water with Aquarium Refractometer Remarkable Accuracy Easy Reading
SunGrow$13.37580 rev
Trending
90-day click momentumDigital Salinity Meter 3-in-1 Saltwater Tester Specific Gravity Salinity & Temperature Pen Hydrometer High Accuracy Water Quality Tester for Aquarium Marine Pool Hydroponics Aquaculture
Anbachi$48.864.1★
Salinity Refractometer for Aquarium Seawater Marine Fishkeeping Salinity Tester 0-100PPT & 1.000-1.070 Salinity Hydrometer Slatwater Refractometer with Automatic Temperature Compensation (ATC)
Hallocool$16.254.5★
SunGrow Measure Salinity of Water with Aquarium Refractometer Remarkable Accuracy Easy Reading
SunGrow$13.374.5★
Seawater Salinity Refractometer Automatic Temperature Compensation Seawater Salinity Hydrometer 0-100ppt & 1.000-1.070 Salinity Specific Gravity Tester for Aquarium Pool Tank Marine Fishkeeping
V·RESOURCING$15.274.4★
Agriculture Solutions Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium 0-100 PPT with Automatic Temperature Compensation
Agriculture Solutions$17.944.6★
What buyers say about refractometer saltwater aquarium
What buyers praise and complain about, mined from review topics.What buyers love
“Simple to use”
“Works as advertised”
“The optical quality is excellent with clear”
“which is economical”
“Durable, Accurate”
“The battery life has been great so far”
“Same design and everything”
“Has everything included”
“This is a very handy tool for making sure the salinity in a saltwater aquarium is accurate”
“The build quality feels solid with good weight and durable construction”
What buyers complain about
“Did not work at all”
“Not worth it”
“Cheap”
“A lil tough to read without readers”
“Way too dim”
Top return reasons
Common questions
- Is refractometer saltwater aquarium profitable to sell on Amazon United States?
- The niche generates $54K/yr across 7 tracked products. 90-day search growth is -11.3%. Flapen's verdict: Skip it (39/100).
- How competitive is the refractometer saltwater aquarium niche?
- 7 brands and 10 sellers compete. The top 5 products take 93% of clicks and top 5 brands hold 93% of demand.
- What do buyers complain about in refractometer saltwater aquarium?
- Top complaints mined from reviews: Functionality-Overall, Value For Money, Quality-Overall. The return rate is 2.9%.
- When does demand for refractometer saltwater aquarium peak?
- Demand peaks in Jan–Aug–Sep; the busiest month runs 2.4× the quietest.
- What does it cost to enter the refractometer saltwater aquarium niche?
- Listings span $13.37–$48.86; the average listing price is $20.49 (sweet spot $15–$100). The average incumbent carries 1,248 reviews — the moat a new listing must climb.