Hydrometer 1.000 to 1.030 specific gravity
4.2
5
10
10
works great
I bought the Instant Ocean Hydrometer and it was a great value! Further more, this was my first time ordering from this website and I must say I'm very happy! I ordered a bag of Florida crushed coral (40lbs), an aquarium background, an Instant Ocean hydrometer, and a bag of Instant Ocean salt mix (50 gallon) on 5-16-12 and received everything today on 5-19-12! It wasn't supposed to come for 7 days, so needless to say I'm very happy!
May 21, 2012
Great
Works perfect as many before me have mentioned make sure any bubbles on needle are off and make sure to rince before and after to ensure no buildup on needle. if you have the money go for a refractometer as it is more accurate. if your on a budget this works fine and is accurate enough.
May 3, 2012
A very good hydrometer
I chose the IO hydrometer partly because of the name, but mostly because of its larger size and ease of reading. The numbers are spaced out nicely over an even arc rather than being crammed together so taking a reading is easy. Even if it's not perfectly level the reading doesn't change around because of the space between the numbers.
It reads 1.000 for tap water after I rinse it out so I know there is no salt or calcium deposits throwing the reading off. It is 100% precise which is more important than accuracy because stability is more important than the actual specific gravity. This unit never requires calibration or temperature conversions. It just works.
Always make sure there are no air bubbles on the needle and make sure to rinse it out well before and after every use.
April 10, 2012
Good hydrometer
I bought this hydrometer after having problems with the accuracy of another model and it reads pretty close to the refractometer at the LFS. Fill it slowly to avoid bubbles on the needle though. I have found that it's hard to knock them off once they are there.
February 8, 2011
 "Instant Ocean Hydrometer")
Instant Ocean's durable, clear acrylic, swing-arm hydrometer is easy to use and easy to read. Full-range results in both salinity and specific gravity (0 to 40 ppt salinity and 1.000 to 1.030 specific gravity) with color-blocked "safe zone" to make routine testing quick and accurate. Features large swing-arm pointer, extra-wide stable base and "easy-dip" design to keep your hands dry while obtaining water sample. Temperature-corrected for use between 68° and 85°F with specific gravity readings accurate to ± 0.001.
