How does everybody calibrate their refractometers?

[erich]

Do I need calibration fluid or is my ro water ok?

 

[fishpoop]

you will need calibration fluid.
RO water is an inaccurate way to calibrate a refractometer for use in our hobby.

http://youtu.be/lo8JQWj5vJg

 

[erich]

Thanks fishpoop for the info. Just got my first refractometer for my bday. Where can i buy the calibration fluid?

 

[Pufferpunk]

Do a search for the cheapest.

 

[Tangency]

One of CR sponsors bulk reef supply sells salinity calibration fluid:
http://aquarium.bulkreefsupply.com/search?asug=&view=grid&cnt=12&w=calibration

There are group buys to BRS frequently... jump in on the next order.

 

[DB9181]

i believe distilled water should read 0.000 as well

 

[Hyperlitexr50]

I use the fluid from BRS and double check with RO water.

 

[FishBeard]

i believe distilled water should read 0.000 as well

Will read 1.000 technically. And my refractometer has always read 1.000 on DI water after calibrating to 35ppt solution.

 

[fishpoop]

Thanks fishpoop for the info. Just got my first refractometer for my bday. Where can i buy the calibration fluid?

in your area, Beyond the Reef

i believe distilled water should read 0.000 as well

in our hobby we are not looking for a calibration to '0' which is why so many hobbyists have inaccurate readings. we need to calibrate to a reading of 35ppt or a SG of 1.0264 and that is why the calibration fluid is required.

 

[Pufferpunk]

http://blog.captive-aquatics.com/captive_aquatics/2011/01/refractometer-calibration-the-myth-and-risks-of-using-rodi.html

 

[William Lutman]

+1 distilled water

 

[Pufferpunk]

Read that link I posted.

 

[MMreef]

Calibration fluid 35 ppm

 

[madjoe]

Lol am i the only one still useing the plastic float one and mine is 9 years old lol

 

[erich]

I calibrated my refractometer with ro water. Then I checked it with aqua craft calibration fluid. They did not match. Calibration fluid read 1.022. Instead of 1.026. Instructions for refractometer said to calibrate with distilled water. Had my water tested at lfs and it matched my reading with my refractometer when calibrated with ro water. Is my calibration fluid off?

 

[fishpoop]

I calibrated my refractometer with ro water. Then I checked it with aqua craft calibration fluid. They did not match. Calibration fluid read 1.022. Instead of 1.026. Instructions for refractometer said to calibrate with distilled water. Had my water tested at lfs and it matched my reading with my refractometer when calibrated with ro water. Is my calibration fluid off?

in our hobby we are not looking for a calibration to '0' which is why so many hobbyists have inaccurate readings. we need to calibrate to a reading of 35ppt or a SG of 1.0264 and that is why the calibration fluid is required.

Eric, the chances are very good that the LFS you went to has an inaccurate reading as well. I know of many LFS in our area that calibrate with RO/DI or distilled water as stated in the instructions. As I posted earlier however, we need to calibrate to 35ppt, not "0"....when calibrated to 35ppt with the proper solution, our refractometers will read RO/DI or distilled water at <0 (below "0")

 

[tkh]

I've got to say - I was also under the impression DI water was fine until I read this thread, my tank and creatures thank you guys! My calibration was way off.... Luckily its fixed now!

 

[KeishaKornbread]

I've got to say - I was also under the impression DI water was fine until I read this thread, my tank and creatures thank you guys! My calibration was way off.... Luckily its fixed now!

This is why folks need to stop recommending DI water. It's bad advice and can cost folks everything in their tanks.

 

[Pufferpunk]

This is why folks need to stop recommending DI water. It's bad advice and can cost folks everything in their tanks.

Everyone except Joe!

 

[EricTheRed]

http://blog.captive-aquatics.com/captive_aquatics/2011/01/refractometer-calibration-the-myth-and-risks-of-using-rodi.html

This is perhaps the best general advice I've heard in a long time...

If there's a moral in the story, it's that, as one of my favorite songs says, "universal truth isn't measured in mass appeal." So remember, if 90% of people say one thing is the way to go, it doesn't mean it's actually the best plan, especially when the 10% who are actually qualified to answer the question say otherwise.

Looks like I'll be adding calibration solution to my shopping list...