Instant Ocean Hydrometer accuracy?

Sgt Jonny Cat

Sgt Jonny Cat

Member
Hello all, I am almost 3 weeks into my 55 gallon cycle. I have live sand live rock and I test the water every other day (ammonia, nitrite, and nitrate and SG) I have an instant ocean hydrometer. Is this thing accurate? Meaning mine reads my salt level at around 1.022.

Will a different hydrometer read something different or are these reliable?
 
I have a instant ocean and a fluval hydrometer. They do read a little different from each other. I don't know if they were calibrated at different temps or what. They both read lower than my refractometer, but it wasn't too bad.

Refractometers are a lot nicer to use and a lot of them have temp correction. A few drops if water on the prism, wait 30 seconds and look through the eyepiece.

My refractometer reads different than the hydrometers too. Then there's my fluval g3 with a conductivity probe that reads lower than all if them and I'm not sure what to think. I trust my refractometer over all the others.
 
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IMO, just get yourself one of those $7.99 floating glass hydrometers and be done with it.

My parents used to use the same thing back in the late 70's early 80's, and the design is still the same now in 2014. It just goes to show, they work... KISS
 
It will buy u time before u buy a refractometer, mine was off by .02 and most will eventually get off track but it will take some time, at first there good
 
Spend the extra $10.00 and get a refractometer (with calibration fluid) and save yourself a potential future headache
 
Hydrometers seem to vary from each other, and can also very depending on water temp.
A refractometer really is the way to go.
 
toss that in the trash.... dont mean to be blunt but hydrometer's are complete junk! spend the $40 and get a refractometer from brs ( http://www.bulkreefsupply.com/catalog/product/view/id/843/ )
i owned one in the beginning because i didn't know any better...my hydrometer was off by 3 ppm... hydrometer read 1.026 when my salinity was really 1.029... not only are they extremely accurate but simple to use and takes secs to use also it will last a lifetime... that refractometer i just posted comes with the calibration solution, adjustment tool, while cloth, and a hard case to store everything.
 
Sgt Jonny Cat said:
Hello all, I am almost 3 weeks into my 55 gallon cycle. I have live sand live rock and I test the water every other day (ammonia, nitrite, and nitrate and SG) I have an instant ocean hydrometer. Is this thing accurate? Meaning mine reads my salt level at around 1.022.

Will a different hydrometer read something different or are these reliable?
Click to expand...

They are junk.... my IO would read 1.025. I would then measure with my Milwaukee refractometer (one of the best you can buy), and it was actually 1.027-28... waaaaay off. Ditch it and spend the money for a good refractometer.
 
It's ATI very good refractometer I have it too

qeqyjydu.jpg
 
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I bought mine without the case for like $8-10 new lol
It's calibrated with my RO water so it's simple.

The swing arms are can be .02 to .03 off if used right and no bubbles on your swing arm. And refrec meters normally .01 off depending on how well you calibrate it.

Just remember to wait about. 30 seconds after putting your saltwater onto the glass to read it so the auto temp has time to calibrate.

And FYI I got mine off eBay new you don't have to spend a lot to get one. And if you read even the digital milwalki meter is still +\- .01
 
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Sgt Jonny Cat said:
Hello all, I am almost 3 weeks into my 55 gallon cycle. I have live sand live rock and I test the water every other day (ammonia, nitrite, and nitrate and SG) I have an instant ocean hydrometer. Is this thing accurate? Meaning mine reads my salt level at around 1.022.

Will a different hydrometer read something different or are these reliable?
Click to expand...

Despite the other comments on this thread, the results with a poorly calibrated, incorrectly-scaled or incorrectly used refractometer will be just as questionable as an uncalibrated hydrometer.

I note this simply because the method of refractometry isn't inherently better than hydrometry. In fact, a high precision hydrometer (the floating kind, used in a tall cylinder) is still the reference standard when it comes to laboratory measurements.

In answer to your specific question, the IO hydrometers are reliable if they're calibrated and correctly cleaned after use. From the factory, they typically read lower than the actual specific gravity. My experience has been that they're usually low by about 0.004. But the only way to know for sure is to either make your own standard solution, or compare it to a properly calibrated instrument (usually a refractometer) at a LFS.

If you are uncertain whether you can use/calibrate a scientific instrument like a manual refractometer, there's a pretty bullet proof solution that requires almost no skill by the user to get correct results - a digital refractometer. Most of us use the Milwaukee brand because it's relatively inexpensive and accurate. But even with this instrument, you should still be a refractometry standard solution - just zeroing any refractometer with distilled water/RODI isn't enough to ensure accurate results.
 
Very well put dkeller. I have seen numerous refractometer threads and most are due to improper calibration. Any instrument is only as good as it's calibration. Following the manufacturers directions and the use of proper zero and span solutions is a must.

FWIW I use a hydrometer and a Myron L company Ultrameter II for conductivity, TDS and Temperature.
 
Thats just common sense...theres no calibration solution for a hydrometer and that's why any refractometer you buy comes with 35ppm calibration solution now as per the instructions they say to calibrate before evert test but once you get a feel for yours you'll know how long till you'll need to recalibrate...mines lasts about 2 weeks till it begins to read slightly off
 
I've been using the instant ocean hydrometer for about six months with zero issues.

I don't buy into the hype. ;)
 
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