Best Salinity Tester

[thepeefer]

Hello everybody, I have just started my first saltwater tank and am wondering on what is the best salinity tester. I want something that is accurate and easy to use. Preferably under $80.
TIA

 

[Gumbies R Us]

https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html This is one of the best ones you can buy.

However if you want a digital one I would go with this one https://www.bulkreefsupply.com/hi98319-marine-salinity-tester-hanna-instruments.html

 

[Mr. Mojo Rising]

I love my hanna tester !

 

[Kilman805]

The Tropic Marin hydrometer has been great for me. It’s very precise, easy to read, and doesn’t need calibration. Its only disadvantages are that you need a pretty deep volume of water to float it and it’s thin glass, so fragile.

I don’t like the calibration uncertainty of electronic testers and refractometers. But they are convenient and lots of people use them too.

 

[Dbichler]

I use both the tropic marine just buy a 500 ml cylinder and then the Hannah which always is .02 low for mine.

 

[AmazingYocool]

Hello everybody, I have just started my first saltwater tank and am wondering on what is the best salinity tester. I want something that is accurate and easy to use. Preferably under $80.
TIA

Aquarium systems full range hydrometer. Around 20$. But a mechanical hydrometer for 100$ is very good aswell

 

[rhaetuluscrenatus]

tropic marin hydrometer, it's good to compare in reference with electronic salinity tester

 

[RWReefer]

I’ll second the tropic Marin glass hydrometer. Pick up a 500mL flask along with it to isolate the equipment from your tank so it doesn’t break, because it is fragile.

 

[fishyjoes]

The easy to use testers aren't super accurate or lose calibration (so you must recalibrate often, making them not so easy)
I use a tropic marin high precision hydrometer - it big and delicate (thin glass, easily broken) but accurate and precise (and doesn't need calibration)

 

[thepeefer]

The easy to use testers aren't super accurate or lose calibration (so you must recalibrate often, making them not so easy)
I use a tropic marin high precision hydrometer - it big and delicate (thin glass, easily broken) but accurate and precise (and doesn't need calibration)

Are hydrometers better then refractometers?

 

[fishyjoes]

Are hydrometers better then refractometers?

It's a trade off depending on what you call "better".

I have a refractometer as well. It's compact, easy to calibrate, and only takes a couple of drops of water to test, but I can't really tell with high precision what the value is - the distance between the lines is very small (1.025 vs 1.026 is like a half millimeter) - though this may be good enough for many people.

The tropic marin high precision hydrometer (that one specifically, not a "swing arm hydrometer") is over a foot long and requires about 450ml of water to test (I have a 500ml graduated cylinder) - but the readings are much easier to see. The lines for 1.0260 vs 1.0261 (notice one more decimal place) is one millimeter apart.

I think they cost about the same, but you must handle the glass hydrometer with care or it will break. A refractometer is unlikely to ever break unless you're really trying.

 

[thepeefer]

I think the hydrometer would be a bit hard for me to handle. Is there any alternative?

 

[Kilman805]

Are hydrometers better then refractometers?

With typical refractometers, each tick on the scale corresponds to 0.001 SG, so for example, you’re guessing the difference between 1.0250 and 1.0260. On top of that, they need calibration.

With the Tropic Marin hydrometer, each tick corresponds to 0.0001 SG, so you’re guessing the difference between 1.0260 and 1.0261. The difference between 1.0250 and 1.0260 is unmistakable. And the measurement method is directly based on the water density, so there’s never any need to recalibrate. It’s calibrated at 77 degF, so very close to typical tank temperature.

So for me, it’s an easy yes. The hydrometer is better. Yes, you need to be careful because it’s glass. Not a big deal.

 

[slingfox]

VeeGee makes the best refractometer. It is not cheap but worth every penny.

 

[Randy Holmes-Farley Verified Community Expert]

Best implies some sort of criteria. Is it cost? Highest accuracy? Easiest to use? Fastest to use? Continuous reading? Provides other data (such as temp)? Direct reading vs having to look up temperature corrections? Durability? Potential interferences?

Different methods and different devices will win, depending on what the criteria chosen are. No device wins them all.

 

[BetteMidler]

However you measure your salinity, measure it the same every time. I use a refractometer with a calibration solution. I went so far to mix up Randy's calibration solution & it simply matched the one I bought off Amazon

Typically, I measure my salinity twice with a refractometer. I apply two drops, let it sit in the window for 20-30 seconds, read. I clean the window with a microfiber cloth and test again. The second reading is what I always use. As long as you mixed water matches the tank, you are fine, but I usually use the calibration solution prior to water changes or any adjustments in salinity to a tank. i.e. my quarantine tank. I've only had to adjust the refractometer once in over a year in my experience.

I would suggest to always mix a known amount of salt to water ratio for water changes. I use food scale & a line on my mixing container. Always weigh it the same way and fill the container in the manner every time.

If you get water from another source, like the bag of water from a fish store or online purchase, always measure it and your tank and compare the difference. Any questions, use the calibration solution. This way, you know the salinity difference regardless.

The point is, take measurements the same way every time.