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Amazon Best Sellers
Our most popular products based on sales. Updated hourly.
Best Sellers in
Aquarium Hydrometers
#1
Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium 0-100 PPT with Automatic Temperature Compensation
4.7 out of 5 stars
1,738
$19.88
#2
Coralife Energy Savers ACLAF877 Deep Six Hydrometer
4.3 out of 5 stars
620
$8.27
#3
Aquarium Salinity Refractometer with ATC Function,Saltwater Test Kit for Seawater, Pool, Aquarium, Fish Tank.Dual Scale: Specific Gravity & Salt Percent
4.6 out of 5 stars
288
$17.99
#4
Exo Terra Terrarium Hydrometer
4.4 out of 5 stars
1,115
$5.25
-
$13.66
#5
GXSTWU Reptile Hygrometer Thermometer LCD Display Digital Reptile Tank Hygrometer Thermometer with Hook Temperature Humidity Meter Gauge for Reptile Tanks, Terrariums, Vivarium
4.4 out of 5 stars
315
$12.55
-
$22.55
#6
SunGrow Measure Salinity of Water with Aquarium Refractometer, Remarkable Accuracy, Includes Calibration Tool, Ensures Overall Health of Plant and Marine Life, Easy and Clear Reading
4.1 out of 5 stars
295
$14.95
#7
Digital Salinity Tester for Salt Water - Aquarium Salinity Meter with ATC, IP67 Waterproof, 0-200 PPT Large Range Multi-Parameter Tester for Seawater, Fish Tank, Hydroponics
4.3 out of 5 stars
13
$36.99
#8
Coralife BioCube Mini Aquarium Hydrometer
3.1 out of 5 stars
62
$14.62
#9
TRZ Salinity Refractometer for Aquariums, Marine Monitoring, Saltwater Testing, Dual Sacle 0-100ppt Salinity & 1.000-1.070 Specific Gravity Automatic Temperature Compensation.
4.2 out of 5 stars
114
$19.80
#10
RZ Aquariums Salinity Refractometer for Seawater Marine Fish-Keeping, Dual Scales Specific Gravity Salinity Meter Hydrometer 0-100ppt & 1.000-1.070, Saltwater Tester with ATC Function
4.6 out of 5 stars
356
#11
Fluval Sea Hydrometer for Aquarium, Medium
3.7 out of 5 stars
398
$8.81
-
$23.45
#12
Aichose Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium, Saltwater Pool, with ATC Function, Dual Scale: Salinity 0-100‰ and Corresponding Specific Gravity
4.5 out of 5 stars
42
$19.99
#13
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
4.7 out of 5 stars
844
#14
Seawater Salinity Refractometer,V-Resourcing Automatic Temperature Compensation Sea Water Salinity Measurer for Aquarium, Hydrometer, 0-100ppt & 1.000-1.070 Salinity Specific Gravity
4.5 out of 5 stars
44
$15.99
#15
Pen Type Salinity & Temperature Meter ATC NaCl Salt Water Quality Tester for Saltwater Aquarium Hydroponics Food
3.8 out of 5 stars
105
$32.90
-
$34.90
#16
Pet Dog & Cat Refractometer,V-Resourcing Pet Urine Specific Gravity (1.000~1.060) Clinical Refractometer with Serum or Plasma Protein Test (2~14 g/100ml) for Veterinary Cat,Dog, Pets
4.7 out of 5 stars
29
$16.99
#17
KOOBOOK 1 Pcs Accurate Hydrometer Salinity Meter 1.000-1.027 Salinity Range 0-36 for Aquarium Fish Tank Marine Sea Saltwater
3.4 out of 5 stars
12
$8.99
#18
Abuycs Salinity Refractometer for Seawater and Marine Fishkeeping Aquarium, Saltwater Tester Hydrometer, Dual Sacle 0-100ppt & 1.000-1.070 Specific Gravity with ATC Automatic Temperature Compensation
4.6 out of 5 stars
12
#19
POPETPOP Aquarium Saltwater Hydrometer, Automatic Salinity Hydrometer, Salt Water Salinity Meter Salinimeter for Fish Tank (Rectangle Type)
$8.99
#20
Instant Ocean SeaTest Hydrometer
4.2 out of 5 stars
442
$8.99
-
$21.99
#21
Tiaoyeer Salinity Refractometer with ATC Refractometer for Seawater, Pool, Tank, Testing, Marine, Fishkeeping, Dual Scale-Specific Gravity 0-100PPT & 1.000-1.070
4.2 out of 5 stars
5
$19.99
#22
ZRM&E Seawater Hydrometer for Aquarium Aquaculture Seawater Densimeter Ocean Hydrometer Salinity Meter for Fish Tank Salinity Specific Gravity Test
3.7 out of 5 stars
7
$8.99
#23
Hikari AccuProbe Aquarium Hydrometer, Full
4.4 out of 5 stars
11
$13.87
#24
capetsma Salinity Tester, Accurate Sea Hydrometer Aquarium Marine Salinity Meter for Fish Tank Pond Water Saltwater Freshwater Specific Gravity Test
4.0 out of 5 stars
79
$9.99
#25
KKmoon Salinity Refractometer, Handheld Seawater Hydrometers, Optical Salinity Tester, Portable ATC Refractometer, Dual Scale Saltwater Tester for Aquarium, Seawater, Pool, Fish Tank
4.2 out of 5 stars
18
$18.99
#26
Actopus Hydrometer Salinity Tester for Aquarium Sea Fish Tank Salt Water
$8.99
#27
Rhino Clinical Pet (Dog & Cat) Refractometer HR305 (ATC), Urine Specific Test
5.0 out of 5 stars
9
$27.70
#28
Accurate Automatic Hydrometer Salt Water Salinity Meter Salinimeter for Fish Tank (Long Type)
4.0 out of 5 stars
13
$10.19
-
$13.39
#29
Dual Scale Salinity Refractometer ATC 0-100ppt (0-10%) & 1.000-1.070 Specific Gravity, Portable Meter Tester for Seawater Salt Sea Water Aquarium Brackish Reef Tank Marine
4.6 out of 5 stars
56
$21.90
#30
emours Aquarium Gloves Waterproof Elbow Length Long Sleeve Scratch Resistant Work Gloves 27-Inch
4.3 out of 5 stars
44
$15.99
#31
Semetall Salinity Tester Transparent Acrylic Aquarium Sea Hydrometer Salinity Meter Salinity Specific Gravity Test for Fish Tank Pond Water Saltwater Freshwater
#32
Dr. Marine Saltwater Marine Aquarium Salinity Portable Refractometer Meter ATC 0~10% reef
5.0 out of 5 stars
1
$63.64
#33
Gain Express Clinical Refractometer with ATC, Tri Scale Serum Protein/Urine Specific Gravity/Refractive Index
4.7 out of 5 stars
10
$23.90
-
$24.90
#34
AUTOUTLET Salinity Refractometer for Aquarium Salinity Tester with ATC and Dual Scale 0-100‰ & 1.000-1.070 Specific Gravity Saltwater Tester for Seawater Pool Fish Tank
4.7 out of 5 stars
18
$19.99
#35
Pet Dog Cat Refractometer Pet Urine Specific Gravity Refractometer Serum Plasma Protein: 2~14g/dl, Clinical Animal Refractometer Hydrometers Urine Tester 1.000-1.060SG for Veterinary Cat Dog Pets
4.1 out of 5 stars
9
$16.99
#36
Aeroway Salinity Refractometer, Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.)
4.6 out of 5 stars
45
2 offers from
$32.00
#37
Rhinoco Salinity Refractometer, Saltwater Aquarium Refractometer, Dual Scales Specific Gravity Salinity Meter with 0-100 PPT and 1.000-1.070 for Seawater, Pool, Tank, Testing, Marine Fishkeeping
4.6 out of 5 stars
12
$17.69
#38
Amzdeal Salinity Refractometer Aquarium & Seawater - Dual Scale (1.0 to 1.070 S.G.)
4.3 out of 5 stars
59
$29.89
#39
Aquarium Equip UP Glass Saltwater Hydrometer - Reef Soft Coral Salinity Marine Fish Shrimp sea
4.0 out of 5 stars
9
#40
Automatic Temperature Compensation Sea Water Salt Salinity Refractometer for Aquarium, 0% - 10% & 1.0 to 1.070 S.g. Dual Scale Hydrometer By Adeadvancedoptics
3.9 out of 5 stars
145
$22.18
#41
Kocome Marine Hydrometer Reef Fish Tank Aquarium Water Salinity Specific Gravity Tester
3.9 out of 5 stars
11
$6.99
#42
TOPINCN Square Saltwater Hydrometer Salt Water Salinity Meter Accurate Automatic Hydrometer Salt Water Salinity Meter for Fish Tank
5.0 out of 5 stars
1
$9.49
#43
Tylu Handheld Breeding Salinometer Refractometer Hydrometer Tester for Seawater and Marine Fishkeeping
#44
Sera Marin Hydrometer
4.0 out of 5 stars
73
$15.49
#45
Premium Salinity Refractometer with Automatic Temperature Compensation for Saltwater, Aquarium, Marine Reef Tank Testing - Dual Scale (0-100ppt & 1.000 to 1.070 S.G.)
4.5 out of 5 stars
18
$19.95
#46
Eyourlife Salinity Refractomer Aquarium Optical Optics Refractometer with Auto Temperature Compensation ATC Digital Dual Scale Salinity Meter Hydrometer Specific Gravity for Saltwater Seawater Marine
4.4 out of 5 stars
18
$24.29
#47
COCODE Refractometer Salinity ATC Hydrometer Aquarium Dual Scale Optical Salinity Meter Specific Gravity Automatic Temperature Compensation for Pool Sea Water Fish Tank Testing
5.0 out of 5 stars
10
#48
Folding Salinity Meter Professional 0‑100ppt High Presision for Outdoor for Swimming Pool for Aquarium
$40.69
#49
Signstek ATC (Automatic Temperature Compensation) Dual Scale Sea Water Salinity Refractometer Meter Salimeter Measurement Tool for Aquarium and Seawater Monitoring, 0% - 10% & 1.0 to 1.070 S.G
4.3 out of 5 stars
55
#50
Neptune Systems AquaController Apex - Lab Grade PH Probe
3.8 out of 5 stars
13
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