Unexpected problem with refractometers... lol

[Myka]

Can I just go to the beach and get a cup of salt water and use that calibrate my refractometer?

No. Salinity will vary at the surface, and in different locations around the world.

 

[Randy Holmes-Farley]

Can I just go to the beach and get a cup of salt water and use that calibrate my refractometer?

As mentioned, no. This map shows large scale variations, but evaporation, rain, and local land input of freshwater impacts salinity locally too:

https://www.nasa.gov/sites/default/files/images/591162main_pia14786-43_full.jpg

 

[Paul B]

That map is a perfect example why it is not that important to have your salinity at exactly where you believe it should be.

 

[Randy Holmes-Farley]

That map is a perfect example why it is not that important to have your salinity at exactly where you believe it should be.

But don't you prefer light orangy yellow to dark yellowy green?

 

[Paul B]

Actually I think that map is correct. I see New York where I live as purple with very low salinity. I collect water here and sometimes it is so weak I can probably keep kissing gouramies or water my orchid collection with it, that is if I had an orchid collection, which of course, I don't.
I am not exactly sure what the salinity of my tank is, but as long as the fish stay in the tank and don't try to come in bed with me, I think the salinity is close enough to whatever it is supposed to be. :cool: