Hanna and Refractometer 12ppt different

[Robert Ranciato]

What got me to get a refractometer was I took a small cup of my tank water a week ago to one of the LFS here (not my main go to) and read a high salinity through a refractometer that I thought possibly may have been an error (or that my sample had some evap since it was like 100ml although had a lid).

Could both Hanna pouches of calibration fluid be a bad batch that I calibrated both my Apex probe and Hanna checker to? I floated them in my 78° tank water before calibrating.

Worst case if I come to find out my tank is at 42ppt, how fast should I lower? 1ppt a day?

I’m going to bring another sample to get tested at my main LFS and also bring both salinity testers to find out tomorrow.

I had the same problem I have a cheep refractometer and it never matches hanna checker. I go with the hanna because it matches closely to one of those cheep float checkers. Take your hanna checker to the lfs to see what it says.

 

[Reefer Matt]

lol I can’t not see it on the packs now. Don’t know how I missed that! Doh!

No prob! It is confusing, and I thought the same at first. I don't even have the salinity tester, but a customer wanted a few of these packets, so I ordered a whole box, and thought I could use the rest on my refractometer. I had the same problem, so then I read the package too!

 

[KrisReef]

@Randy Holmes-Farley , here is a photo of the current packaging.

The print on this pouch is too small to be accurate imo probably a huge source of errors.

 

[robotrash]

Make a diy refractometer calibration fluid.
It is better to calibrate refractometer to fluid than rodi water regardless of the directions.

Look in here for it.

https://reefkeeping.com/issues/2004-06/rhf/index.php

Do you think a standard food scale would be accurate enough to make this solution? We don't drink soda so no 2L bottles here! Just wanted to get an idea of how you go about it (if you do)

 

[Reefering1]

I got a milligram scale(.00x) from Amazon for 20 or 30 dollars and scaled the recipe for 10ml. Read through the article, it's all in there. Works perfect

 

[Reefering1]

Guess its $50 now

 

[fishyjoes]

Do you think a standard food scale would be accurate enough to make this solution? We don't drink soda so no 2L bottles here! Just wanted to get an idea of how you go about it (if you do)

1 Liter water = 1 kg, easy if your food scale is accurate and shows grams

 

[robotrash]

1 Liter water = 1 kg, easy if your food scale is accurate and shows grams

I more meant for the insanely specific amount of salt but that's great to know! Thank you!