Pinpoint Calibration Fluid

[Capt. Nemo]

I'm having a problem trying to calibrate my refractometer with this calibration fluid. I place 2-3 drops on the main prism and then turn the calibration screw to get the upper blue field and the lower white field to meet exactly on the 0.0 ppt or 1.00 spec. grav. However, I have turned the screw as far as it goes and yet I cant get the blue field any lower than 1.010. I then tried DI water and it worked. The bottle for this calibration fluid has a label that says this: +- 1% @77 degrees F. Can someone tell me how to calibrate my RHS 10ATC refractometer.

Thanks,
Gary

 

[IndyReefMan]

If you are using Pinpoint Salinity Calibration Fluid, you should be calibrating your refractometer to 35 ppt, not 0 ppt.

 

[jen bee]

i calibrate to 0 with ro water

 

[Pennoyer]

First test fresh ro/di-- set it to 0. then use the calibration fluid and re-set to 1.026. HTH

 

[stereomandan]

It has been found that many of the refractometers can be off if you calibrate to zero with RO/DI water. I still need to calibrate with the pinpoint calibration fluid, and am curious if mine has been off for the last 4-5 years.

Dan

 

[jen bee]

i calibrated with randys solution as well, was right on

 

[Pennoyer]

Mine was off (low) by .006 when I calibrated with the pinpoint solution. I've read this is pretty much the same thing found by most people with this refractometer. I always battled low magnesium levels, which makes sense now since the tank was at 1.019 instead of 1.025 where I thought it was. Since making the change my magnesium levels have stabilized at a higher level without supplementation. Best $3.50 I've spent on the tank since the turkey baster