What salinity tester should I trust?

[Adamantium]

I’m so frustrated, guys. My refractometer (calibrated) is giving me 1.022, my Hanna salinity tester (calibrated) is giving me 1.026, and my new Tropic Marin High Precision Hydrometer is giving me 1.0278.

My tank is happy, so I’ll probably just do an ICP test to get a more accurate number, but man, I wish non “hobby grade” equipment was more accessible. This just kills my faith in the accuracy of these things. I know it’s all about stability, though, so I’ll just stick with what I’m doing.

Thanks for reading my rant.

 

[Dbichler]

I would say tropic Marin high precision would be most accurate hard to mess that up

 

[Adamantium]

I would say tropic Marin high precision would be most accurate hard to mess that up

I imagine you’re correct, but what if it was miscalibrated at the factory? Impossible to know.

 

[Dbichler]

Can’t imagine too many are made wrong.

 

[Adamantium]

Can’t imagine too many are made wrong.

Odds are you’re right. I trust the refractometer the least, so I’ll just call that reading erroneous.

 

[Hydrored]

I found out Hanna was reading consistently .002 too low and was confirmed when my ICP came back say check salinity. Bought a Misco and confirmed, I’ll never look at another device other than the Misco

 

[Adamantium]

I found out Hanna was reading consistently .002 too low and was confirmed when my ICP came back say check salinity. Bought a Misco and confirmed, I’ll never look at another device other than the Misco

Oof, that’s definitely a bit out of my budget.

 

[uhgster1]

Don’t fret. If you are using calibrating fluid, calibrate the refractometer to what it tells you to and measure your water against it. I use BRS calibrating fluid. I don’t worry about brands. As long as you’re consistent your water will be good.

 

[Adamantium]

Don’t fret. If you are using calibrating fluid, calibrate the refractometer to what it tells you to and measure your water against it. I use BRS calibrating fluid. I don’t worry about brands. As long as you’re consistent your water will be good.

That’s what’s so confusing. I did right calibrate it right before I took that measurement. It’s showing way lower than the hydrometer.

 

[uhgster1]

That’s what’s so confusing. I did right calibrate it right before I took that measurement. It’s showing way lower than the hydrometer.

I feel your pain. That’s why I just stick with one and drive on. If the tank is happy just be consistent with the tester you’re using.

 

[Reef.]

I imagine you’re correct, but what if it was miscalibrated at the factory? Impossible to know.

you could say that about the ICP report too...you know it’s all about stability, least with the TM refractometer if it is wrong it will be the same amount of wrong for ever, you can’t say that about the others.

 

[blasterman]

Still using my plastic instant ocean floating needle wheel hydrometer thingy. Gotta be 15 years old when I paid $10 for it. Dropped enough most of the base is cracked off.

I checked it against a couple calibrated refractometers and its within a point. No calibration required. Floating plastic doesn't require calibration. Ive dropped/lost my past two refractometers and dont miss them. Sooner or later I will drop it or sit on it and that will be it.

 

[Rmckoy]

Still using my plastic instant ocean floating needle wheel hydrometer thingy. Gotta be 15 years old when I paid $10 for it. Dropped enough most of the base is cracked off.

I checked it against a couple calibrated refractometers and its within a point. No calibration required. Floating plastic doesn't require calibration. Ive dropped/lost my past two refractometers and dont miss them. Sooner or later I will drop it or sit on it and that will be it.

I have 3 of these old swing arm hydrometers .
They all read different
Calibrating a refractometer frustrates me . I’ve always used rodi water to calibrate

the Hannah checker is easy but again requires calibrating .

I’m seriously thinking of trying the tm hydrometer similar to the bobbing one I had almost 25 years ago

 

[Adamantium]

I have 3 of these old swing arm hydrometers .
They all read different
Calibrating a refractometer frustrates me . I’ve always used rodi water to calibrate

the Hannah checker is easy but again requires calibrating .

I’m seriously thinking of trying the tm hydrometer similar to the bobbing one I had almost 25 years ago

It's basically the same as the bobbing one, but with a much higher resolution, and supposedly greater accuracy. You can easily read to the ten thousandths place.

 

[PatW]

The refractometer is fine. Every now and then, mine needs calibration for which I use BRS calibration fluid. But my hydrometer is not really precise. I figure I can about plus or minus .0003. The good thing with a hydrometer is all it takes is a tiny sample so if you have fish or coral or whatever in a bag, you can check it.

I would think the high precision hydrometer will be the most precise. But you hope that their calibration of it is OK.

But marine critters do fine at slightly different salinities, but the LOVE stability. The hydrometer should be best at tracking that.

 

[Adamantium]

The refractometer is fine. Every now and then, mine needs calibration for which I use BRS calibration fluid. But my hydrometer is not really precise. I figure I can about plus or minus .0003. The good thing with a hydrometer is all it takes is a tiny sample so if you have fish or coral or whatever in a bag, you can check it.

I would think the high precision hydrometer will be the most precise. But you hope that their calibration of it is OK.

But marine critters do fine at slightly different salinities, but the LOVE stability. The hydrometer should be best at tracking that.

One thing about the high precision hydrometer is that it’s anything but small. I have to fill a 14” tall 500ml graduated cylinder to use mine, and it barely fits.