In my experience the Apex salinity monitor has never been very accurate, at least not more accurate than +/- 1-2 ppt. It normally sways around through about a 1.5-2 ppt range over the day/night when I know salinity in my tank is constant. It is helpful to alert for big-picture problems like detecting an ATO failure but not for an actual reading.
I always manually check with my Milwaukee when I want to know my salinity. And when I do I double check the Apex against it to make sure it hasn’t drifted too far.
The new Milwaukee MA887 Seawater Digital Refractometer encompasses 3 different types of user selected scales for the measurement of seawater providing for a much more precise evaluation. Each scale is temperature compensated. PSU - The newest type scale standard – Letters stand for Practical...
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