Should I trust my calibration fluid

[LxHowler]

I have just bought some brightwell calibration fluid for my refractometer, I use to use acurasea but I couldn't get more of that. With acurasea it said my tank was always at 1.025 salinity but now I have calibrated with brightwell it says I am well under that.

This is what it reads with the new calibration to brightwell. I was under the illusion that when calibrated my ro should read 0 so I tried that and it was way under.

I was wondering if I should trust this new calibration fluid as it is the only thing that has changed but now says all of my perameters are way off what they were before.

This is what my tank reads now. Sorry for the low quality photos. All of the water was at the same temperature when tested. I don't know what I should do now, should I raise my tank salinity, should I return the brightwell and get a different one or should I calibrate to ro water?
Any help would be greatly appreciated.

 

[Garf]

I have just bought some brightwell calibration fluid for my refractometer, I use to use acurasea but I couldn't get more of that. With acurasea it said my tank was always at 1.025 salinity but now I have calibrated with brightwell it says I am well under that.

This is what it reads with the new calibration to brightwell. I was under the illusion that when calibrated my ro should read 0 so I tried that and it was way under.

I was wondering if I should trust this new calibration fluid as it is the only thing that has changed but now says all of my perameters are way off what they were before.

This is what my tank reads now. Sorry for the low quality photos. All of the water was at the same temperature when tested. I don't know what I should do now, should I raise my tank salinity, should I return the brightwell and get a different one or should I calibrate to ro water?
Any help would be greatly appreciated.

Make your own solution to use.

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

 

[LxHowler]

Make your own solution to use.

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

Thanks I will give that a try

 

[Randy Holmes-Farley]

Most hobby refractometers are not true seawater refractometers but are brine refractometers and they SHOULD NOT read 0 ppt correctly when properly calibrated at 35 ppt.

I discuss that issue and more here:

Refractometers and Salinity Measurement - REEFEDITION

Title photo by R2R member Rskillz By Randy Holmes-Farley Salinity is one of the most important parameters measured in reef aquaria. It controls not only the salt balance between an organism and its surrounding environment, but also the levels of a host of ions Read more here...

www.reefedition.com

 

[Usctom]

I'v had similar issue with different calibration fluids. At one point i had 3 different ones and one that I made. Now I just use RO water and make sure it is Zero. Not perfect but it gets you close

 

[LxHowler]

Most hobby refractometers are not true seawater refractometers but are brine refractometers and they SHOULD NOT read 0 ppt correctly when properly calibrated at 35 ppt.

I discuss that issue and more here:

Refractometers and Salinity Measurement - REEFEDITION

Title photo by R2R member Rskillz By Randy Holmes-Farley Salinity is one of the most important parameters measured in reef aquaria. It controls not only the salt balance between an organism and its surrounding environment, but also the levels of a host of ions Read more here...

www.reefedition.com

Oh right I didn't realise that. I have never calibrated to ro I just thought that was the case as my fluid was reading so off what my others did.

 

[Garf]

I'v had similar issue with different calibration fluids. At one point i had 3 different ones and one that I made. Now I just use RO water and make sure it is Zero. Not perfect but it gets you close

Hmmm. If I calibrate mine to 1.026 using RODI its actually closer to 1.021 in the real world. I would never use RODI.

 

[ryshark]

I have just bought some brightwell calibration fluid for my refractometer, I use to use acurasea but I couldn't get more of that. With acurasea it said my tank was always at 1.025 salinity but now I have calibrated with brightwell it says I am well under that.

This is what it reads with the new calibration to brightwell. I was under the illusion that when calibrated my ro should read 0 so I tried that and it was way under.

I was wondering if I should trust this new calibration fluid as it is the only thing that has changed but now says all of my perameters are way off what they were before.

This is what my tank reads now. Sorry for the low quality photos. All of the water was at the same temperature when tested. I don't know what I should do now, should I raise my tank salinity, should I return the brightwell and get a different one or should I calibrate to ro water?
Any help would be greatly appreciated.

I had this same issue today with a new bottle of brightwell. It is 5ppm off my previous bottle. In fact I found this thread by searching exactly for this issue. When my refractometer is calibrated to my old solution, which I think is accurate, my refractometer is set at 35ppt then I put the new solution in and it reads 40ppt. I’ve had this happen twice now, not 100% sure which one is accurate, but I think the old bottle is correct.
I’m going to try Randy’s recipe tomorrow, except divide the salt and water by 4.
2-liters is way too much, even the 60ml bottle lasts forever.

 

[LxHowler]

I had this same issue today with a new bottle of brightwell. It is 5ppm off my previous bottle. In fact I found this thread by searching exactly for this issue. When my refractometer is calibrated to my old solution, which I think is accurate, my refractometer is set at 35ppt then I put the new solution in and it reads 40ppt. I’ve had this happen twice now, not 100% sure which one is accurate, but I think the old bottle is correct.
I’m going to try Randy’s recipe tomorrow, except divide the salt and water by 4.
2-liters is way too much, even the 60ml bottle lasts forever.

I agree. I think that it is the brightwell that's the issue. My old fluid seemed to be accurate, I am also going to make a home made solution. I also tested my tank with a hydrometer, I know these aren't perfect but that read 1.025. So far everything has read 1.025 except the brightwell so I guess that's the issue

 

[Randy Holmes-Farley]

I'v had similar issue with different calibration fluids. At one point i had 3 different ones and one that I made. Now I just use RO water and make sure it is Zero. Not perfect but it gets you close

What refractometer? For most sold to hobbyists, that RO method you use is inherently wrong, even if the refractometer was made perfectly and you are using it perfectly.

 

[ryshark]

I just got Triton ICP results back and my NA is 10215 mg/l which on their chart is a little low. So maybe, the new Brightwell Solution is actually correct? I need to figure out now if there is a way to convert the mg/l into SG or Salinity.

 

[ryshark]

I just got Triton ICP results back and my NA is 10215 mg/l which on their chart is a little low. So maybe, the new Brightwell Solution is actually correct? I need to figure out now if there is a way to convert the mg/l into SG or Salinity.

I just found a calculator online and this is equivalent to 32.5 and I thought I was at 35. So according to Triton both of my calibration solutions are off by about 2.5 in opposite directions.

 

[Randy Holmes-Farley]

I just found a calculator online and this is equivalent to 32.5 and I thought I was at 35. So according to Triton both of my calibration solutions are off by about 2.5 in opposite directions.

Hold on. How did you calculate salinity? What calculator? Triton would fail miserably to determine the salinity of my correct salinity solution by ICP because it is not a seawater mimic, and there's no reason a standard should be.

 

[ryshark]

Hold on. How did you calculate salinity? What calculator? Triton would fail miserably to determine the salinity of my correct salinity solution by ICP because it is not a seawater mimic, and there's no reason a standard should be.

Thanks for looking into this Randy, I used this calculator to convert Triton's NA mg/l reading of my sample to Salinity

Seawater Composition Calculator

Aquarium calculator; Estimate the concentrations of selected ions in natural seawater at a given salinity.

www.hamzasreef.com

So you think I should not trust my actual water is around 32.5 using the Triton reading and this calculator?

 

[Randy Holmes-Farley]

Thanks for looking into this Randy, I used this calculator to convert Triton's NA mg/l reading of my sample to Salinity

Seawater Composition Calculator

Aquarium calculator; Estimate the concentrations of selected ions in natural seawater at a given salinity.

www.hamzasreef.com

So you think I should not trust my actual water is around 32.5 using the Triton reading and this calculator?

Did you have values for all of those chemicals in the fluid?

 

[ryshark]

Did you have entries for all of those chemicals in the fluid?

Did you have entries for all of those chemicals in the fluid?

All I did was switch NA on the right column to mg/l and then went to the left column and started guessing salinity until the NA on the right column matched my NA reading from Triton closely.

 

[ryshark]

All I did was switch NA on the right column to mg/l and then went to the left column and started guessing salinity until the NA on the right column matched my NA reading from Triton closely.

But, yeah I guess I do have them all from the Triton, but I didn't plug them all in. I don't think it will allow me to.

 

[Randy Holmes-Farley]

All I did was switch NA on the right column to mg/l and then went to the left column and started guessing salinity until the NA on the right column matched my NA reading from Triton closely.

by NA, you mean sodium?

I would not trust that to be accurate by itself. Mixes often have elevated other things like calcium and magnesium that will depress sodium at a fixed salinity. My standard would be way off.

 

[ryshark]

by NA, you mean sodium?

I would not trust that to be accurate by itself. Mixes often have elevated other things like calcium and magnesium that will depress sodium at a fixed salinity. My standard would be way off.

Yeah, Triton just puts Na, I'm assuming Sodium. I'm going to make a 1/4 batch of your recipe tonight and see where that comes in at. Thanks.

 

[LxHowler]

Just thought I'd update this again. I made some of the solution linked above and that read the same as my previous acurasea solution which leads me to believe the brightwell is the issue, I'm guessing a bad bottle as all the reviews say its good. Is there anything else I should try before returning this for my money back?