Four Salinity Testers, Four DIFFERENT results - Which do you trust?

[Steverd]

I tested water in two of my reef tanks and got four different results from each - See Photo.
Which do you trust and what do YOU Use?

1. Salinity Refractometer for Seawater (calibrated)
2. Instant Ocean 10+ years old
3. hygger Salinity Tester
4. Coralife Aquarium Fish Tank Deep Six Hydrometer

I have been using the Instant Ocean Hydrometer for years, but now what I thought was 1.023 water might be 1.027
Is there something better I should be using? Thoughts?

 

[Euphylliaphyle]

Get a Tropic Marin high-precision hydrometer. Good timing: Black Friday sale at BRS:
https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

 

[ILOVEYOUHALFISH]

I trust my refractometer, that I calibrate every time I use it ;)

 

[Quietman]

Get a Tropic Marin high-precision hydrometer. Good timing: Black Friday sale at BRS:
https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

This for the last few years. Just drop it in tank, read it and done. Just be careful when handling. Also it isn't temp corrected but that's very minor in our ranges. There are calculators online of course.

 

[Pod_01]

Nice collection, I used to have similar number of devices and similar results.

These days I use TM Hydrometer

Get a Tropic Marin high-precision hydrometer. Good timing: Black Friday sale at BRS:
https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

Best money I ever spent,

Good luck

 

[Poseidons Reef]

I tested water in two of my reef tanks and got four different results from each - See Photo.
Which do you trust and what do YOU Use?

1. Salinity Refractometer for Seawater (calibrated)
2. Instant Ocean 10+ years old
3. hygger Salinity Tester
4. Coralife Aquarium Fish Tank Deep Six Hydrometer

I have been using the Instant Ocean Hydrometer for years, but now what I thought was 1.023 water might be 1.027
Is there something better I should be using? Thoughts?

Tropic Marin hydrometer. I made a tube out of 4 inch PVC pipe with a cap on one end. Fill it close to the top and spin the hydrometer to get rid of any air bubbles. Very accurate each time and no calibration need.

 

[King Sweetcorn]

Nice collection, I used to have similar number of devices and similar results.

These days I use TM Hydrometer

Best money I ever spent,

Good luck

Do you need any calibration solution for it?

 

[Euphylliaphyle]

Do you need any calibration solution for it?

No.

 

[GSPClown94]

I tested water in two of my reef tanks and got four different results from each - See Photo.
Which do you trust and what do YOU Use?

1. Salinity Refractometer for Seawater (calibrated)
2. Instant Ocean 10+ years old
3. hygger Salinity Tester
4. Coralife Aquarium Fish Tank Deep Six Hydrometer

I have been using the Instant Ocean Hydrometer for years, but now what I thought was 1.023 water might be 1.027
Is there something better I should be using? Thoughts?

If you trust the solution used to calibrate the refractometer then trust the refractometer. If you haven’t checked the others with any kind of standard solution then you can also do that. Randy has some diy calibration standards for different salinity measuring instruments around here somewhere.

 

[Steverd]

Get a Tropic Marin high-precision hydrometer. Good timing: Black Friday sale at BRS:
https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

Thanks for the Black Friday Tip, I just got a free box of Tropic Marin salt from BRS this week from my last order. That was a really nice freebie for sure!

 

[GSPClown94]

If you trust the solution used to calibrate the refractometer then trust the refractometer. If you haven’t checked the others with any kind of standard solution then you can also do that. Randy has some diy calibration standards for different salinity measuring instruments around here somewhere.

Here http://reefkeeping.com/issues/2004-06/rhf/

 

[Steverd]

If you trust the solution used to calibrate the refractometer then trust the refractometer. If you haven’t checked the others with any kind of standard solution then you can also do that. Randy has some diy calibration standards for different salinity measuring instruments around here somewhere.

I calibrate with RO water and then 1.0264 Specific Gravity solution by Continuum Reagents and the refractometer was right on the 1.026.
I guess I will trust this until my Tropic Marin High Precision Hydrometer arrives, I ordered it last night from BRS.

 

[atoll]

Get a Tropic Marin high-precision hydrometer. Good timing: Black Friday sale at BRS:
https://www.bulkreefsupply.com/high-precision-hydrometer-tropic-marin.html

IMO thats the best and most accurate.

 

[Steverd]

IMO thats the best and most accurate.

Thank you, so many people have recommended this, that I did order it from BRS, now just have to wait a week for it to arrive (hope it's not broken in shipping),.

 

[Randy Holmes-Farley Verified Community Expert]

No.

But, of course, if you have never checked it, you don't know if it is accurate or inaccurate every time. lol

 

[Randy Holmes-Farley Verified Community Expert]

Thank you, so many people have recommended this, that I did order it from BRS, now just have to wait a week for it to arrive (hope it's not broken in shipping),.

I recommend making an appropriate standard yourself, and not rely on others to do things properly.

https://www.reef2reef.com/ams/reef-aquarium-salinity-diy-calibration-standards.956/
from it for a refractometer:

In order to provide a standard for refractometers, a solution whose refractive index is similar to normal seawater is required. Seawater with S= 35 has a refractive index of 1.3394.1 Likewise, the refractive index of different sodium chloride solutions can be found in the scientific literature. My CRC Handbook of Chemistry and Physics (57th Edition, Page D-252)4 has such a table. That table has entries for 3.6 and 3.7 weight percent solutions of sodium chloride that span the value for normal seawater. Interpolating between these data points suggests that a solution of 3.65 weight percent sodium chloride has the same refractive index as S=35 seawater, and can be used as an appropriate standard (Table 2).

This 3.65 weight percent sodium chloride solution can be made by dissolving 3.65 grams of sodium chloride in 96.35 grams (mL) of purified fresh water.

 

[atoll]

Mine and IME the best.

 

[Euphylliaphyle]

But, of course, if you have never checked it, you don't know if it is accurate or inaccurate every time. lol

Ignorance is bliss! But I look at it this way: I get very consistent results, very close to what I need. And isn't stability the better part of the whole point? Besides, I checked it for deviation against my reference standard, my trusty IO plastic swing arm hydrometer! lol

 

[atoll]

Ignorance is bliss! But I look at it this way: I get very consistent results, very close to what I need. And isn't stability the better part of the whole point? Besides, I checked it for deviation against my reference standard, my trusty IO plastic swing arm hydrometer! lol

You may as well have tested it against your swinging left arm as long as you don't use deodorant under it your good to go

 

[Randy Holmes-Farley Verified Community Expert]

Ignorance is bliss! But I look at it this way: I get very consistent results, very close to what I need. And isn't stability the better part of the whole point? Besides, I checked it for deviation against my reference standard, my trusty IO plastic swing arm hydrometer! lol

That’s a fine point. Reef tank salinity is not something that needs to match a narrow target.