NANFA-- salinity

Nicholas J. Zarlinga (
Wed, 4 Apr 2001 12:28:42 -0400

At 25C a 6.6 ppt salinity is 1.003. At 23C a 5.9ppt salinity is 1.003. And
at 19C a 6.0ppt salinity is 1.004. As you can see is it temperature
dependent and relatively insignificant to most freshwater fish. I am
currently treating 3 muskies in a 1% NaCl solution which corresponds to
about 1/3 seawater or about 12 ppt salinity. Using a refractometer will
give you the most accurate determination of "salt" in the water because is
measures the salinity where a hydrometer is much more variable since it is
temperature dependent. With that said, it is usually only critical in lab
work or if you are at the maximum end of what a fw fish can take in which
instrument you use. Event saltwater fish can take a very wide range of
salts in the water. You might want to check out and of the books that
Stephen Spotte has written. He has more than you ever would like to know
about this and all other aspects of the aquarium hobby. His best work is
his latest, Captive Seawater Fishes. As with other books, he has charts
which can give you the info you need.

Nick Zarlinga
Aquarium Biologist
Cleveland Metroparks Zoo
216-661-6500 ex 4485

"Fish worship... is it wrong??" (Ray Troll)

original message

Date: Sat, 28 Apr 2001 09:38:13 -0400
From: "Bob Bock" <>
Subject: NANFA-- ppt vs. specific gravity

Does anyone know how to relate parts per thousand of sodium to the specific
gravity of sea water? What specific gravity would water with a salinity of
six parts per thousand have?

Thanks, all.

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