Caution for anyone using a refractometer

[Reefer Rob]

The problem is that a lot of the refractometers that find their way into the aquarium industry are for measuring brine, as in for the pickling industry. Our salt water has a lot of other major elements that also effect the refractive index of the water.

According to Pinpoint, their calibration fluid also works well to calibrate our refractometers.

Here's the original thread that spawned Randy's article.

[Doo]

so - aside from the PINPOINT product - are there other products that can be picked up locally??

[Reefer Rob]

Originally Posted by Doo

so - aside from the PINPOINT product - are there other products that can be picked up locally??

As far as I know Pinpoint is the only one. Thats what everyone who posts on RC is using. Alternatively you could find a buddy that uses a well calibrated salinity monitor on their tank, and use their tank water to check your refractometer.

[Delphinus]

Ah, ok... verrrrry interesting. Thanks for the synopsis, fkshiu.

Reference fluids of 35ppt seawater are a brilliant idea. I really wish most testers we have would have this available. I know Seachem testkits used to have reference solutions but I stopped using Seachem when they changed their reagents so that it the colour changes were so faint it was impossible to use.

The only tester (electronic or otherwise) that I have any degree of confidence in is my Pinpoint NO3 meter, and that's because you need to calibrate at the endpoints of the measuring scale for every test. You can use the calibration fluids as the reference. Reference solutions ought to be an industry standard, that way if you have any doubt about a reading, you can at least still verify your testing. Oh well, [/rant]