Temperature and Salinity

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yippee
Posts: 3
Joined: Tue Aug 14, 2012 5:31 pm

Temperature and Salinity

Post by yippee »

Hi

My tank salinity varies from 34.5 to 35.5 ppt throughout the day and this seems correlated to the change in temperature (~26.5 to 27.6 deg). Is anyone seeing such a big change in salinity?

Do I need to worry over them?
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High Temp and Sal
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Low Temp and Sal
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rimai
Posts: 12881
Joined: Fri Mar 18, 2011 6:47 pm

Re: Temperature and Salinity

Post by rimai »

Yes, conductivity is highly affected by temperature and we measure salinity by means of conductivity.
There is no temperature compensation.
Ahmedess calculated the factor to compensate and was included in the libraries, but not being used at the moment.
The problem with that formula is that it does not take in consideration the temperature where the initial calibration was performed. If you perform the calibration at around 25C or 75F, you are fine to use his formula, but if you go away from this temperature, the formula doesn't apply anymore. That's why it has not been used.
http://forum.reefangel.com/viewtopic.php?p=7386#p7386
Roberto.
yippee
Posts: 3
Joined: Tue Aug 14, 2012 5:31 pm

Re: Temperature and Salinity

Post by yippee »

Thanks! Shall look into the compensation details. Or may just stick to what it is now since that reflects the true value(s).
alexwbush
Posts: 327
Joined: Tue Mar 22, 2011 12:45 am
Location: San Diego, CA

Re: Temperature and Salinity

Post by alexwbush »

rimai wrote:Yes, conductivity is highly affected by temperature and we measure salinity by means of conductivity.
There is no temperature compensation.
Ahmedess calculated the factor to compensate and was included in the libraries, but not being used at the moment.
The problem with that formula is that it does not take in consideration the temperature where the initial calibration was performed. If you perform the calibration at around 25C or 75F, you are fine to use his formula, but if you go away from this temperature, the formula doesn't apply anymore. That's why it has not been used.
http://forum.reefangel.com/viewtopic.php?p=7386#p7386
VERY interesting. This I did not know. I might have to mess with this.
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