salinity tester
Worth a lookShows a sweet-spot price point ($29.90 avg), but soft demand (-1.7% this quarter) keeps it on the watch list.
Avg price
Incredible$29.90avg listing price — sweet spot $15–$100
Price range
Great$6.95–$92.61cheapest to priciest tracked listing — scored on the share inside $15–$100
Quality gap
Great4.1★avg incumbent rating — lower means beatable quality
Conversion
Great7.2%search→purchase rate — share of searches ending in a sale
Review moat
Good900.94avg incumbent reviews — the moat a new listing must climb
Brand share
Good71%top-5 brand share — brands hold most of the demand
Returns
Okay3.2%return rate — above 6% kills the launch gate
Market size
Okay$207K$207K/yr · 96K searches
Growth
Bad-1.7%90-day search growth — must beat 0% to launch
Competition
Bad71%top-5 click share — a locked-up shelf
According to Flapen's Amazon United States niche tracking, salinity tester is a $207K/yr Amazon United States market (96K searches/yr). The top 5 brands hold 71% of demand. Demand peaks in Apr–May–Jun–Jul–Aug. Verdict: Worth a look — 52/100.
Data updated Jul 17, 2026 · scored weekly · How we score niches
salinity tester market data
- Units sold / yr
- 6K–8K
- avg 250–500/product
- Revenue / yr
- $179K–$239K
- units × avg price
- Launch success
- —
- 2 of 2 new (360d)
- Conversion rate
- 7.2%
- Avg BSR
- #61
- Page quality
- 0%
- Prime
- 94%
- Sponsored
- 83%
- Out of stock
- 1.4%
- Avg brand age
- 51 months
- Avg seller age
- 181 days
Competition & brand share
The top 5 products capture 71% of clicks — a locked-up shelf that new listings rarely crack.Brands
17 rising
Sellers
43
Top-5 brand share
71%
Top 20: 100%
Top-5 click share
71%
Top 20: 100%
Open market
24%
- Agriculture Solutions25%
- Hofun22%
- Coralife10%
- Hallocool8%
- Anbachi5%
- hygger5%
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -1.7% search growth over the last 90 days.Peak months: Apr, May, Jun, Jul, Aug · busiest ÷ quietest = 2.6×
Top salinity tester search terms
- salinity tester35K/yr
- salinity tester for saltwater aquarium21K/yr
- salinity meter15K/yr
- hydrometer for saltwater aquarium5K/yr
- saltwater tester3K/yr
- salinometer6K/yr
- salinity3K/yr
- aquarium salinity tester4K/yr
- hydrometer aquarium4K/yr
Top salinity tester 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 18 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
Pool Salt Tester & PH Meter Hofun Digital Salinity Meter and PH Tester for Aquarium and Pool Saltwater Water 5 in 1 Salinity PH Temp EC and TDS Meter Aquarium Swimming Pool Hot Tub High Accuracy
Hofun$36.024.3★1,898 rev
Coralife Aquarium Fish Tank Deep Six Hydrometer For Measuring Water Salinity PPT and Specific Gravity
Coralife$13.664.1★1,505 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
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
Newest
by launch date
EZTOCH Pool Salinity pH Tester Hydrogen Water Tester 7 in 1 pH Salt ORP H2 TDS EC Temp Meter for Salt Water Pool Hydrogen TDS PPM Tester for Drinking Water pH EC ORP Meter for Hydroponic Water
EZTOCH$38.6036 rev
Pool Salt Tester & PH Meter - 5-in-1 Digital TDS Meter for Salinity PH Temp and EC 0.01 High Accuracy Swimming Pool Hydroponics Aquarium Hot Tub PPM Meter for Pool Drinking Water Wine Food
ZTGHFMY$29.1521 rev
YINMIK Pool Salinity pH Meter pH Salt Reader for Saltwater Pool Hydroponic pH EC Meter pH PPM Tester 5 in 1 pH Salt Conductivity TDS Temp Test Kit Digital pH Tester for Aquarium Aquaponics Koi
YINMIK$14.6984 rev
WLR Industries Hanna HI98319 Marine Salinity Tester Checker
WLR Industries$90.4046 rev
T TESTRUST Pool Salt Tester - Multifunctional 5 in 1 Salinity PH TDS EC and Temperature Meter Pool Salinity Testing Kit Digital Salinity Tester for Swimming Pool Saltwater Sea Water Aquarium
T TESTRUST$32.17244 rev
Trending
90-day click momentumEZTOCH Pool Salinity pH Tester Hydrogen Water Tester 7 in 1 pH Salt ORP H2 TDS EC Temp Meter for Salt Water Pool Hydrogen TDS PPM Tester for Drinking Water pH EC ORP Meter for Hydroponic Water
EZTOCH$38.604.3★
Pool Salt Tester & PH Meter - 5-in-1 Digital TDS Meter for Salinity PH Temp and EC 0.01 High Accuracy Swimming Pool Hydroponics Aquarium Hot Tub PPM Meter for Pool Drinking Water Wine Food
ZTGHFMY$29.153.1★
ZHIZHOU Marine Hydrometer Reef Fish Tank Aquarium Water Salinity Specific Gravity Test
ZHIZHOU$6.953.6★
YINMIK Pool Salinity pH Meter pH Salt Reader for Saltwater Pool Hydroponic pH EC Meter pH PPM Tester 5 in 1 pH Salt Conductivity TDS Temp Test Kit Digital pH Tester for Aquarium Aquaponics Koi
YINMIK$14.693.9★
T TESTRUST Pool Salt Tester - Multifunctional 5 in 1 Salinity PH TDS EC and Temperature Meter Pool Salinity Testing Kit Digital Salinity Tester for Swimming Pool Saltwater Sea Water Aquarium
T TESTRUST$32.174.4★
What buyers say about salinity tester
What buyers praise and complain about, mined from review topics.What buyers love
“Easy to use and accurate, as far as I can tell”
“The build quality is solid”
“As advertised”
“price is very good”
“Works Great”
“still going strong”
“The instructions are clear”
“Seems to be pretty durable”
“Made a good construction”
“The battery life has been great so far”
What buyers complain about
“Stopped working after one use”
“Does Not Work”
“Terrible seller for not having quality control or correcting this problem after so many have reviewed this product as very inaccurate”
“Its definitely more expensive than basic testers”
“it will be rather difficult to use it”
“Confusing instructions”
“the calibration was way off on both”
“Not new”
“Broke after one use, water seeped in and inaccurate tester”
“the button doesn't work”
Top return reasons
Common questions
- Is salinity tester profitable to sell on Amazon United States?
- The niche generates $207K/yr across 18 tracked products. 2 of 2 products launched in the last 360 days are still selling. 90-day search growth is -1.7%. Flapen's verdict: Worth a look (52/100).
- How competitive is the salinity tester niche?
- 17 brands and 43 sellers compete. The top 5 products take 71% of clicks and top 5 brands hold 71% of demand.
- What do buyers complain about in salinity tester?
- Top complaints mined from reviews: Durability, Functionality-Overall, Quality-Overall. The return rate is 3.2%.
- When does demand for salinity tester peak?
- Demand peaks in Apr–May–Jun–Jul–Aug; the busiest month runs 2.6× the quietest.
- What does it cost to enter the salinity tester niche?
- Listings span $6.95–$92.61; the average listing price is $29.90 (sweet spot $15–$100). The average incumbent carries 901 reviews — the moat a new listing must climb.