Accurately Measure Your Aquarium's Specific Gravity with Instant Ocean SeaTest Hydrometer

By: Instant Ocean

The Instant Ocean SeaTest Hydrometer is the perfect choice for any aquarium. It's easy to use and read, plus it's incredibly accurate. With a clearly marked scale, it's simple to get accurate results in no time. This hydrometer also tests salinity and specific gravity, helping you keep your tank in perfect condition. The design of the meter makes it easy to dunk into the aquarium, and you can be sure that you're getting reliable readings. If you're looking for the best aquarium hydrometer, the Instant Ocean SeaTest Hydrometer is the perfect choice.

Key Features:

Accurate readings for your marine aquarium are now available with our full-range tests! Our tests measure salinity and specific gravity with precision and accuracy, up to +/- 0. Ready to use, these tests will help you maintain a healthy tank environment for your fish and other aquatic life.
80
B2B Rating
284 reviews

Review rating details

Easy to use
83
Easy to read
92
Sturdiness
81
Build quality
80
Overall satisfaction
80
Customer support
85
Packaging
82
Value for money
81
Accuracy
80

Pros and Cons

Pros
  • Features a clearly marked scale that shows readable results
  • Tests salinity and specific gravity in marine aquariums that helps to maintain a healthy tank
  • Comes with a simply designed meter to dunk in aquarium that makes it easy to use
Cons
  • May not be accurate at times

Details of Accurately Measure Your Aquarium's Specific Gravity with Instant Ocean SeaTest Hydrometer

  • Item Length: 6 Inches
  • Department ‏ ‎: Testing Equipment
  • Included Components: Instant Ocean Full-range Hydrometer
  • Color: Whites & Tans
  • ASIN ‏ ‎: B00019JOSO
  • Brand: Instant Ocean
  • Response Time: 500 Milliseconds
  • Is Discontinued By Manufacturer ‏ ‎: No
  • Item model number ‏ ‎: TK504
  • Reusability: Reusable
  • Unit Count: 1 count
  • Product Dimensions ‏ ‎: 1.5 x 5.25 x 8.75 inches; 0.8 Ounces
  • Date First Available ‏ ‎: October 2, 2001
  • Product Care Instructions: Hand Wash Only
  • Display Type: Analog
  • Age Range (Description): All ranges
  • Manufacturer ‏ ‎: Instant Ocean

Comments

Marc Kenemuth: Received item that was ordered. Will use seller again

United States on Jan 18, 2023

JQ: bad quality and package

Canada on Dec 08, 2021

Allison C: Didnt work as well as my old one. Bubbles get trapped under the needle and give inaccurate readings. Ive done everything to keep this from happening but it continues. Switching to a refractometer

Canada on Jun 17, 2019

Catherine M.: The best hydrometer for salt tank!

Canada on Apr 26, 2019

Amazon Customer: Perfect item just what I needed thanks

Canada on Mar 27, 2017

John: This is the second hydrometer of this model that I've owned (they do get erratic over time even when rinsed and stored with RO water, I think because the pivot point wears and also gets precipitate on it). The previous one read one point high, while this one is accurate.

Any plastic swing-arm hydrometer will have issues with air bubbles sticking to the arm when the hydrometer is new -- that's often why people have issues with these things. I soak mine in salt water for about three days, rinsing with RO each day then refilling. That seems to remove the film on the plastic that attracts the air bubbles.

Swing arm hydrometers also should be checked for accuracy. I calibrate them against a (properly calibrated) refractometer. Once I determine how high or low the hydrometer reads, I make a note of that (I use a permanent marker to note on the back of the hydrometer, e.g. "This hydrometer reads 1 ppt high"). Then I have an easy to use, accurate device to do routine checks of salinity (well, actually specific gravity). The more tedious-to-use refractometer is used for periodic sanity checks.

United States on Oct 25, 2016

Michael: i use this for 2 different tanks and have gotten consistent results. the only thing to watch for is bubble on the needle. they will cause significant differences in the reading. on my brackish tank it was showing higher salt then my salt tank due to bubble. just give it a small tap and the bubble comes off and the reading is perfect.

for the money its hard to find a better product

United States on Aug 08, 2015

Datboiconnor: This is a decent measurement tool to see if my tanks salinity is in the right place. I would not recommend this for precise measurements only because it is affected by current, bubbles and salt crystals left behind from previous testing. Make sure you rinse it with tap water to get rid of the salt crystals so it don't affect the next testing. Then dry it out and you should be good. Make sure its level with the ground otherwise your results will be affected.

Pros
-Good for a general measurement
-Easy to use

Cons
-Multiple factors may affect your end result but with a little care it preforms well
-Clean after usage

United States on Aug 06, 2015

MrRich: I happen to live near the ocean,, so I have the luxury of testing it against a control system. I took several samples of ocean water at various depths and away from shore to see what the actualy salinity was. Then I made a mark on it to set the salinity of my fish tank.. (.038) anyway,, I live in the south pacific in the marshall islands.. It seems a little high,, so either the gauge is slightly wrong or the water has more salt than what wikipedia says it should be for the tropics.

United States on Feb 06, 2014

Accurately Measure Your Aquarium's Specific Gravity with Instant Ocean SeaTest Hydrometer Ade Advanced Optics Dual-Scale Laser Rangefinder - Precise Distance Measurement up to 1,000 Yards! AUTOUTLET Refractometer: Accurately Measure Salinity Levels in Seawater Aquariums
Accurately Measure Your Aquarium's Specific Gravity with Instant Ocean SeaTest Hydrometer Ade Advanced Optics Dual-Scale Laser Rangefinder - Precise Distance Measurement up to 1,000 Yards! AUTOUTLET Refractometer: Accurately Measure Salinity Levels in Seawater Aquariums
B2B Rating
80
97
95
Sale off $3 OFF
Total Reviews 284 reviews 752 reviews 234 reviews
Item Length 6 Inches
Department ‏ ‎ Testing Equipment
Included Components Instant Ocean Full-range Hydrometer
Color Whites & Tans Silvery
ASIN ‏ ‎ B00019JOSO B005ES6MOQ B07CB5KDYL
Brand Instant Ocean AUTOUTLET
Response Time 500 Milliseconds
Is Discontinued By Manufacturer ‏ ‎ No No No
Item model number ‏ ‎ TK504 SSA0010 8541957195
Reusability Reusable
Unit Count 1 count
Product Dimensions ‏ ‎ 1.5 x 5.25 x 8.75 inches; 0.8 Ounces 2 x 2 x 7 inches; 6.4 Ounces 7.87 x 3.54 x 2.36 inches; 8.48 Ounces
Date First Available ‏ ‎ October 2, 2001 July 27, 2011 April 3, 2018
Product Care Instructions Hand Wash Only
Display Type Analog
Age Range (Description) All ranges
Manufacturer ‏ ‎ Instant Ocean No AUTOUTLET
Before you spend your money, check out our reviews. Every time.
Best2buy Newsletter
Don’t miss out on the hottest seasonal and trendy products. Subscribe to our newsletter today.
Don’t miss out on the hottest seasonal and trendy products. Subscribe to our newsletter today.