refractometer calibration fluid...     1/4/12
Good Morning Crew,
I have about refractometer calibration. I recently bought a second refractometer for a friend and it came with Sybon 53.1m calibration fluid. I had been using Pinpoint for the past year and had consistently been getting about 1.024-1.025 in my aquarium. After calibrating with this new solution it came out 1.030. I checked it against what little Pinpoint remained and it showed that the water at 1.025 again.
<Should be reading at 1.0259 at 75 F... as per:
http://premiumaquatics.com/store/merchant.mvc?Screen=PROD&Store_Code=PA&Product_Code=REFRACT-SF&Category_Code=>
 The Sybon solution is what the lfs carries and is relatively inexpensive so I bought another bottle and it showed tested the same as the first bottle. I also checked the newly calibrated refractometer against distilled water, and it gave me a 0 reading. My fish don't seem to be showing any signs of distress, so I have trouble believing my salinity has crept up to 1. 030,
<Me too>
 but I really don't know which I should trust. Any insight on this?
Thanks,
Dave
<I'd check the checker/refractometer against yet another device... I believe the PinPoint device and the calibration fluid readings more than the new refractometer... To me, this last is most likely faulty. I'd send it back for replacement. Bob Fenner>
Re: refractometer calibration fluid
Hello again Bob,
Thanks for the quick response. I guess I should have mentioned I tested this out on two refractometers (the new and old) with both the Sybon and the Pinpoint solution. Now I have a second batch of the
Sybon solution that also tests it at the high reading. I am thinking I should just get online and order another batch of the Pinpoint to see where that gets me. In the meantime, the tank is overdue for a water change. Would the best course of action just be to make salt mix to match what is in the tank and go ahead with the change?
Thanks again,
Dave
<Yes; this is what I would do as well Dave. BobF>