Which salinity tool would you trust?
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JulesH
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Funny you should mention that as I have suspected that my Hanna checker is under reporting the salinity of my tank (considering the error allowance of the tool). I calibrate the checker every month but when compared to my LFS Hanna refractometer it is always low. My LFS checks his refractometer against the Tropic Marin Hydrometer.
I recently purchased a Tropic Marin Hydrometer and started to undertake a comparison with the Hanna checker (see attached graph). The orange line is the Tropic Marin Hydrometer.
I recently purchased a Tropic Marin Hydrometer and started to undertake a comparison with the Hanna checker (see attached graph). The orange line is the Tropic Marin Hydrometer.
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WrasseyReefer
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Yeah, I definitely don’t trust the Hanna. I’ve calibrated my hydrometer, refractometer, and Milwaukee, and they all are very close, while the Hanna is low. Probably won’t be using it anymore.
Randy Holmes-Farley
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There's no such conversion, without knowing the chemical makeup of the standard.
WrasseyReefer
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It’s the Hanna salinity calibration solution. Looks like it’s potassium chloride. Does that help?
I didn't think you could use hanna salinity fluid on a refractometer?
The Hanna checker uses resistance where refractometer uses refraction. 2 different methods.
I use NSW with a pretty well known salinity. My hanna reads this water as expected.
The Hanna checker uses resistance where refractometer uses refraction. 2 different methods.
I use NSW with a pretty well known salinity. My hanna reads this water as expected.
WrasseyReefer
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You’re not suppose to use the Hanna salinity fluid on a refractometer. I shouldn’t have.
I bought a hydrometer from a local store and the paper scale moved. I wouldn't rely on a hydrometer if there is any chance the scale inside can move.
Either a refractometer or the hanna checker. fluid is $2 per calibration and as I said my sea water has a pretty stable salinity so as long as my hanna reads as expected I'm ok with hanna. I still do a calibration once a month or when I think about it.
Randy Holmes-Farley
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It helps, but I do not have a conversion for other devices besides a conductivity meter. It could be done, but would take more time than its worth, looking up changes in refractive index of KCl solutions vs concentration, etc.
peterhos
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Hi There I have just bought the Hanna salinity checker. Also shows temperature so I will now be able to match both the salinity and the temperature when doing a water change. Should have bought one 9 months ago when I started the new tank.
I use this guy with no issues. I calibrate it once a month or so, but have not really had to adjust it.
Vee Gee Scientific STX-3 Handheld Salinity Refractometer with ATC, Industrial-Grade, 0-100% Salinity Range, 1.000-1.070 Specific Gravity Range
Vee Gee Scientific STX-3 Handheld Salinity Refractometer with ATC, Industrial-Grade, 0-100% Salinity Range, 1.000-1.070 Specific Gravity Range
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How do you calibrate it?
It will give inaccurate answers for seawater if you calibrate with pure fresh water.
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I use a refractometer calibrated every use w/ Randy's calibration solution. I am considering an Milwaukee MA887 for convenience but would still check it with Randy's solution. I might be a little paranoid about bad salinity measurements. I almost killed a tank using a swing arm hydrometer a long time ago. That is an experience I don't want to repeat.
SteveMM62Reef
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Deep Six, Available on eBay. If I see a reading that’s questionable. I get out the Refractometer, which is actually junk, compared to the one I have for work. 99% of the time the swing arm is correct. The work ones are for testing Glycol Solutions and Battery Acid. I have two, unfortunately they won’t work for Saltwater. BTW, I have a floating Hydrometer, broke the cylinder it came with. It can be hard to get a reading off of it. Tends to stick to the sides of the Cylinder and water miniscus, makes you wonder where to read it at.
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