Lower temps resulting in lower salt levels - HELP

[bundybass]

My temperature in my reef has been running a little high all summer hovering around 80 degrees. I've noticed over the last week since overnight temps have been dropping that the graph on apex fusion shows salt levels dropping as the temp dropped.

Well last night the house went down to 60 degrees and the tank went from 78.2 down to 77 (managed to get it down to mid 78s over the last few days).

But with this temp drop also came the same drop in salt levels. They have been high but really dropped with the temp. Is this normal?

Here are the graphs from apex fusion:

You can see the downward graph follows almost the same line in both salt and temp. I have only recently started using my apex so I have nothing to compare to.
Does this seem right or is something wrong?

Thanks for your help.

 

[Biglew11]

No experience with the apex salinity probe, but I do know it uses conductivity to measure salinity, this is affected by temperature. Is temperature compensation enabled for the probe.

From neptune forums.
Temperature compensation makes more impact on the Conductivity probe than the pH probe.

The correction factor for pH is about 0.0036 pH/cC at a pH of 8.2 at 25oC (about .01 pH for a 5.4oF (3oC) swing).

Whereas the correction factor for Conductivity is 2.2%/oC at 25oC (about 2.3 PPT at 35 PPT for a 5.4oF (3oC) swing).

A 2.3 PPT swing is much more critical than a .01 swing in pH especially if you are making control or dosing decisions on the measurements.