refractometer off by .005 out of the box?

[FireHouseReef]

So I was noticing the mix directions on my salt kept ending up to high on salinity and it got me thinking maybe my refractometer is off. I decided to calibrate it with RODI water at tank temp and it showed off by .005. That makes my tank salinity 1.019 instead of 1.024. How should I proceed? I did order some 35ppm calibration solution that will be here in a few days. Fish and inverts seem to be doing fine but my one daisy polyp was open the first 2 days I had it and now it hasn't opened for the following 2 days. Thanks in advance for the help.

 

[windemerejack]

You need to calibrate as close to your objective as possible not zero, it might be correct at zero but wrong at 1.026

 

[FireHouseReef]

You need to calibrate as close to your objective as possible not zero, it might be correct at zero but wrong at 1.026

are you saying to mix the salt according to directions then calibrate from that?

 

[KStatefan]

Make a calibration solution and check close to the same measurement you are measuring

 

[windemerejack]

No, calibrate your refractometer with a 1.026 solution.
Think of a car speedo, it shows zero when it has stopped but it might be showing 70 on your speedo when you are only doing 65

 

[mdb_talon]

I would count on it being wrong out of the box. Having said that I agree with others dont make changes until you calibrate using 35 calibration fluid

 

[FireHouseReef]

I would count on it being wrong out of the box. Having said that I agree with others dont make changes until you calibrate using 35 calibration fluid

Thanks I'll wait till the calibration solution gets here.

 

[jtp7004ft]

Mine was off by .010 right out of the box. I check calibration using 1.026 calibration solution before each use (maybe excessive) but, better safe then sorry.