Calibrating Refractometer
 

What are you people using for sloution to recalibrate your refractormeters?

Pinpoint Calibration Fluid 53.0 mS

The only thing I'll ever used

Where can I get this in the south? I'm in cranston

Pinpoint Calibration Fluid 53.0 mS

The only thing I'll ever use

Any brand with 35ppt is good enough for me
I follow the 45 seconds instructions with my ATC

I just use 0ppm rodi water. Dunno if that's the right thing to do but hey it's working n free!!! Lol

what 45 sec instructions are you talking about ?

I have a bottle of Aqua Craft Products, and it states to "Place a few drops of Refractometer Calibration Solution on refractometer prism slide.
Allow 45 seconds if ATC refractometer is used."

My refractometer instructions state this time delay allows the solution to adjust to the ambient temp of the unit. But my unit and solution are kept in the same room - whatever
My instructions also state to cal the unit at 68F. Something to do with it being an ATC unit. Then it is accurate with an ambient shift of 10-30C
So I cal my unit in the basement as it's cooler down there than my 74F upstairs
To each his/her own ...

This is what I do.. I hope it works haha

I used to do this as well but it is much better to calibrate with a known 35 ppt solution such as the pinpoint one listed above.

Using 0 ppm RODI water to calibrate my refractometer, my salinity was acutally at 1.028 when the refractometer was reading 1.025. Didn't know this until after I had used the pinpoint solution to calibrate.

Calibrate??? hmmm...

Where can I buy this?

LFS
Any solution meant to calibrate to 35ppt will do you fine

Well thanks for the replies. So is this solution only available at LFS or anywhere else? The store here would have the deer in the headlights look if I dared to ask.

J&L

I have a bottle of it that I use to calibrate mine once a year, J&L sells it. http://www.jlaquatics.com/product/pp...+Solution.html Or just drop in some time and bring your refractometer with you.

Just in case anyones interested

http://reefkeeping.com/issues/2006-12/rhf/index.php

I have a Sybon refractometer, and have only used the supplied 0 ppt solution to calibrate. I have never had to adjust it. But maybe I should get some of that 35 ppt solution to double check.

I have a sybon, I have calibration fluid and it reads the same if I calibrate it with RODI or the pure water that came with the sybon when I check it with the calibration fluid.

I got some 35 ppt calibration fluid yesterday, and just checked it with my Sybon refractometer. It was bang on perfect. I had previously only checked it with the supplied 0 ppt ultrapure water fluid but have never had to adjust it. Now with the 35 ppt fluid, glad to see that it is accurate at both ends.

I've had the refractometer now for over 3 years, and use it often with water changes and with my QT tank. Not sure how they can get out of calibration, but mine has stayed true the whole time.