Which salinity tool would you trust?

[FrugalReefer]

Used to use a Refractometer. Now I use the Tropic Marin Hydrometer and have never looked back.

 

[JulesH]

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.

 

[WrasseyReefer]

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.

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]

Anyone know what the equivalent salinity is for a refractometer or hydrometer using a 35 ppt conductivity calibration solution?

There's no such conversion, without knowing the chemical makeup of the standard.

 

[WrasseyReefer]

There's no such conversion, without knowing the chemical makeup of the standard.

It’s the Hanna salinity calibration solution. Looks like it’s potassium chloride. Does that help?

 

[PeterEde]

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.

 

[WrasseyReefer]

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.

You’re not suppose to use the Hanna salinity fluid on a refractometer. I shouldn’t have.

 

[PeterEde]

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]

It’s the Hanna salinity calibration solution. Looks like it’s potassium chloride. Does that help?

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]

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.

 

[JoeReefer81]

Hanna's are junk in my opinion. I only trust my Sybon refractometer.

 

[DeniseAndy]

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

 

[Randy Holmes-Farley]

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

How do you calibrate it?

It will give inaccurate answers for seawater if you calibrate with pure fresh water.

 

[ReefGeezer]

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]

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.