Calibrating refractometer

[WhiskeyCoffee]

I just opened up my new refractometer and out of the box it's saying my RO/DI water has 0ppt / 1.0 SG and my tank has 1.027 SG. Should I even bother trying to calibrate this? Some of the Amazon reviews state they took it straight to the LFS to test and theirs were already calibrated...

 

[R33FLIF3]

yes you need to calibrate your refractometer closer to a usable range! once calibrated you will notice your di water is off from 0ppm

 

[WhiskeyCoffee]

Bump #reefsquad

 

[saltyfilmfolks]

temperature effects calibration. the lfs is nuts.
Heres Randy.
http://reefkeeping.com/issues/2006-12/rhf/

 

[jsker]

Yes I took mine to the fish store to check mine against there and found mine was off. We determined that I need a better refractometer, but what I do is know were there is reading and where mine is reading and I check my water to that. I have a controller and just double check to make sure.

 

[jsker]

yes you need to calibrate your refractometer closer to a usable range! once calibrated you will notice your di water is off from 0ppm

Good answer

 

[Brew12]

I just opened up my new refractometer and out of the box it's saying my RO/DI water has 0ppt / 1.0 SG and my tank has 1.027 SG. Should I even bother trying to calibrate this? Some of the Amazon reviews state they took it straight to the LFS to test and theirs were already calibrated...

In my opinion, calibrating it with RO/DI to zero is better than nothing. Better yet is to create your own calibration standard as Randy describes in this article.
Just remember, this is the recipe for a refractometer. It will not read accurately in a hydrometer.

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

 

[R33FLIF3]

get this calibrate monthly..
http://www.bulkreefsupply.com/aqua-craft-refractometer-calibration-fluid.html

 

[john.m.cole3]

most of em now that I have seen say ATC on them. Stands for automatic temperature controlled. @Brew12 beat me to recommending Randy's recipe for calibration fluid. I calibrate mine every time I use it FWIW.

 

[joeyrm7]

you can buy calibration fluid at BRS I do mine every 2 weeks

 

[WhiskeyCoffee]

I bought calibration fluid on Amazon for $11 and guess what - my refractometer was spot on 1.026.

 

[john.m.cole3]

Hey, that's awesome. I used my refractometer for 4 months before buying calibration fluid.I couldn't keep any corals alive bc my SG was 1.020 . Now I check with calibration fluid every week. It will hold its accuracy as long as you don't drop your refractometer or shake it really hard.

 

[Ty Hamatake]

From what I've heard, calibrating with RODI water can cause problems with accuracy. Due to the fact that you are calibrating it to the lowest end of the spectrum possible, any variance is going to have a much larger effect the higher your SG goes. If you think of it as a graph starting at 0, a one degree variance would be negligible. The higher up the graph you go though the bigger your discrepancy gets. I use the calibration fluid from BRS. Calibrating your refractometer to a value much closer (1.026) to what you are testing for results in less chance for error. Just my 2 cents

 

[reefwiser]

An optical refractometer needs to be calibrated with a 35ppt solution. Not Ro water.

 

[WhiskeyCoffee]

lol @ the people in this thread not reading the posts and thinking we're still talking about calibrating w/ RO water...

 

[saltyfilmfolks]

lol @ the people in this thread not reading the posts and thinking we're still talking about calibrating w/ RO water...

Looks like cyano. 100%

 

[WhiskeyCoffee]

 

[cromag27 Verified Sponsor]

Do not calibrate with rodi water.

 

[WhiskeyCoffee]

lol @ the people in this thread not reading the posts and thinking we're still talking about calibrating w/ RO water...

 

[visioned]

i recalibrate at each water change which is currently bi-weekly.

i do this to ensure my SG never moves more than +/- .001.