Salinity question.

[Lee adams]

Just had some NSW delivered from our local reef..Thought I'd look at the salinity with this device I recieved last week..Why so low? Is the device wrong?

 

[Hugo_Fish]

never trust that device... get yourself a refractometer

 

[Dburr1014]

Just had some NSW delivered from our local reef..Thought I'd look at the salinity with this device I recieved last week..Why so low? Is the device wrong?

It may or may not be.
Has it been calibrated? I'm thinking not.
You can make your own fluid to check it.
After the fluid is made, and the device checked, mark it with a sharpie so you will know everytime.
https://reefkeeping.com/issues/2004-06/rhf/index.php

 

[Mr. Mojo Rising]

I would not trust that device, invest in a quality salinity tester.

 

[Randy Holmes-Farley Verified Community Expert]

Local seawater can be reduced in salinity by land runoff, rivers, etc.

it could also be diluted by a seller adding fresh water to it.

And, of course, the measurement could be inaccurate

 

[Dom]

Just had some NSW delivered from our local reef..Thought I'd look at the salinity with this device I recieved last week..Why so low? Is the device wrong?

That is about the salinity of the water where I live. I'm at the mouth of a harbor where fresh water rivers run into the harbor and out the mouth of the harbor (run off as Randy pointed out).

 

[Sophie"s mom]

Just had some NSW delivered from our local reef..Thought I'd look at the salinity with this device I recieved last week..Why so low? Is the device wrong?

A decent refractometer is the only way to go. You can get a less expensive one, as long as it is one that can be calibrated periodically. They are FAR more accurate.

 

[Lee adams]

We collect and deliver the the NSW ourselves..Absolutely no fresh water inlets anywhere near the reef.. Most probably the device then..I will check and verify ..Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

Looking more closely at that swing arm hydrometer, it is not at all to be trusted because it does not even have the salinity and specific gravity scales properly lined up.

For seawater, 35 ppt has a specific gravity of 1.0264, but those two values are far apart. They may be confusing density with specific gravity, which does not impart confidence.

 

[Lee adams]

Wow..Thanks for that observation..Just took another reading with an old wine hydrometer..This reading is looking a lot more realistic..It will have to do until I can find something here in Asia more fit for purpose..Thanks.

 

[Lee adams]

It may or may not be.
Has it been calibrated? I'm thinking not.
You can make your own fluid to check it.
After the fluid is made, and the device checked, mark it with a sharpie so you will know everytime.
https://reefkeeping.com/issues/2004-06/rhf/index.php

Good idea..Thanks.