Refractometer calibration solution

[hurley]

Does anyone know where you can pick this stuff up in Calgary?

[Skimmer Juice]

Wai's Normally carry's the calibration fluid I got a bottle there not to long ago .

[Zoaelite]

Am I missing something here? I've always calibrated to zero with RO water.

[spit.fire]

Am I missing something here? I've always calibrated to zero with RO water.

same

[Zoaelite]

Okayyyy, so after a little searching apparently zeroing with RO can miscalibrate your reading. Not sure by how much considering I've never had a problem.

That being said I will do the loop, find some of this solution and get back to you guys as to how far off the reading is from zero.

[Skimmer Juice]

Okayyyy, so after a little searching apparently zeroing with RO can miscalibrate your reading. Not sure by how much considering I've never had a problem.

That being said I will do the loop, find some of this solution and get back to you guys as to how far off the reading is from zero.

that is what I always did , until I was reading up on it . Ended up grabbing some from wais and it was out a fair bit , but like you never noticed any issues prior to using the fluid . And have also not had any issues since switching the calibration fluid lol

[crimper]

I always calibrate my refractometer with Distilled Water until I almost killed all my SPS as I can't figure what's wrong with my tank as all parameters seems to be right. After some googling I came across this blog:

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

So I decided to buy a Pinpoint refractometer calibration fluid. I was shocked more than my corals about what I found out. I was running my tank salinity @ 1.030 for the longest time. :redface:

I then check other forums regarding this and there are lots of threads with this discussion.

[crimper]

A thread started by Frogger a few moons ago...

http://www.canreef.com/vbulletin/showthread.php?t=122843&highlight=calibration+fluid

[Myka]

The reason you should use calibration fluid is because the refractometers on the market for marine aquariums are almost exclusively brine refractometers, not seawater refractometers. Brine refractometers don't "see" all the salts in seawater, they only "see" a couple salts. As long as a brine refractometer is calibrated at whichever salinity you want to use, it will be accurate at that salinity only. If you're testing, say, hyposalinity with a brine refractometer calibrated to 35 ppt (1.0264 sg), it won't be accurate at 11 ppt (1.009 sg) for hypo just like it isn't accurate at 0 ppt for RO/DI or distilled water.

Most of the confusion lies in the instructions for brine refractometers which say to use distilled water because if you're testing brine with a brine refractometer then distilled water is a perfectly fine calibration solution to use. Most marine hobby brine refractometers are rebranded, such as Vertex, and they don't bother to put proper instructions for seawater calibration in the packages.

D-D and Red Sea both sell true seawater refractometers. The best ones on the market are made by VeeGee and cost about $160. If you have a true seawater refractometer then distilled wTer can be used to calibrate. You can also calibrate with seawater solution and achieve a dual point calibration which allows you to double check the calibration solution.

Calibration solution is a whole other can of worms...I've noticed they vary by as much as 5 ppt from one brand to the next. I started making my own (Randy Holmes Farley published a recipe, Google it he also explains why brine refractometers read off when calibrated with distilled water) and bought dropper bottles off Amazon (like ones used in test kits or for eye drops) to store it in so that there is no contamination or evaporation. I've found the Two Little Fishies solution to be the most accurate, however it's in a large open top bottle that's prone to evaporation/contamination very quickly even when the lid seems closed well.

[kien]

*suddenly all LFS see a huge spike in people coming in to purchase calibration fluid*

:lol:

[Moogled]

Aw man, now you guys are making me nervous.

I just wipe off the water on my shirt after I'm done LOL.

[crimper]

Calibration solution is a whole other can of worms...I've noticed they vary by as much as 5 ppt from one brand to the next. I started making my own (Randy Holmes Farley published a recipe, Google it he also explains why brine refractometers read off when calibrated with distilled water) and bought dropper bottles off Amazon (like ones used in test kits or for eye drops) to store it in so that there is no contamination or evaporation. I've found the Two Little Fishies solution to be the most accurate, however it's in a large open top bottle that's prone to evaporation/contamination very quickly even when the lid seems closed well.

No need to buy those dropper from Amazon or ebay, if you had used those little "Blue Bottles" from Zeovit as they have droppers. I have used them in making my own calibration fluid. It will last a life time :biggrin:

[jhj0112]

ummm.... am I supposed to calibrate this often? maybe I'm lucky but I have not calibrated it for over 4 years... -.-

Sent from my SM-G930W8 using Tapatalk

[Frogger]

ummm.... am I supposed to calibrate this often? maybe I'm lucky but I have not calibrated it for over 4 years... -.-

Sent from my SM-G930W8 using Tapatalk

Depending on the refractometer you have. My first one a Vertex I needed to calibrate almost every time I used it. My new one a Tropic Eden pro-1 normal seawater refractometer I have only had to tweak it a bit over the past 6 months. I still check it a couple times a month. The Tropic Eden is a way better unit then the Vertex.

Do not use the Sybon Standard Seawater Saline because it is almost 4ppT off.

I use the Pinpoint solution and find it more accurate. Also old calibration solutions are not always accurate.

[calo247]

i wonder if the electronic testers are immune to this problem as they use conductivity?

[Myka]

No need to buy those dropper from Amazon or ebay, if you had used those little "Blue Bottles" from Zeovit as they have droppers. I have used them in making my own calibration fluid. It will last a life time :biggrin:
Not that kind of dropper. A sealed one, like eye drops. An open dropper is prone to evaporation and contamination.


Do not use the Sybon Standard Seawater Saline because it is almost 4ppT off.

I have found the same thing even though it is NIST-certified!! I like the dropper bottle it is sealed in though. It reads the same when it's 6 years old.

[hunggi74]

salinity is the most important and easiest parameter to maintain in this hobby. It dictates the starting point of all the elements in your tank. I use a Sybon refractometer and calibrate before I test any new salt water or the water in my tank. Doesn't take that much time but the results can be disastrous if you've got more sensitive corals and are using a unit that isn't calibrated properly

[Zoaelite]

HOKKAYYYYYY.
So I went and dropped $25 at Picies to get the Two Little Fishies calibration fluid. Who would of thought a 250mL bottle of saltwater... the most plentiful liquid on the planet... would cost $100.00/L...

Talk about profit margin...

Whining about price aside, my salinity which I thought sat at 1.026 has been more around the 1.022 point... for however long.

Now I have had really good success with most everything in my tank, so take this info with a grain of salt (:mrgreen::mrgreen::mrgreen:). I will certainly be slowly raising my salinity but I think this is a strong testament to the power of keeping things stable in the tank.

[Wheelman76]

HOKKAYYYYYY.

So I went and dropped $25 at Picies to get the Two Little Fishies calibration fluid. Who would of thought a 250mL bottle of saltwater... the most plentiful liquid on the planet... would cost $100.00/L...



Talk about profit margin...



Whining about price aside, my salinity which I thought sat at 1.026 has been more around the 1.022 point... for however long.



Now I have had really good success with most everything in my tank, so take this info with a grain of salt (:mrgreen::mrgreen::mrgreen:). I will certainly be slowly raising my salinity but I think this is a strong testament to the power of keeping things stable in the tank.



But is the new calibration fluid correct ? Lol

This is the thing that's so frustrating with these calibration fluids. They all seem to give slightly different readings , and sometimes way off. I bought a bottle of the sybon calibration fluid several months ago , and found my tank water was at 1.030!! Damn I thought , but before making any changes , I had a friend come over with his refractometer and his own fluid. His refractometer said my tank water was 1.022 , so I returned the bottle to my LFS and had them check it. Turns out this bottle was off by .004 , they checked the other 4 bottles of sybon fluid on the shelf , and they were all bang on at 1.026 like they were supposed to be.

Anyhow , just something to think about before you adjust your salinity.

[Zoaelite]

I feel like I'm currently opening the Pandora's box of calibration fluid :neutral:.

Thanks for the heads up, if I paid $25 for overpriced saltwater to nuke my tank I'm going to be rather frustrated...

Anyway to calibrate my calibration fluid without buying more calibration fluid?!

[Brunz]

Anyway to calibrate my calibration fluid without buying more calibration fluid?!

I know this feeling!!!
Very few of us have the equipment necessary to test or correct the equipment we test things with.....wait, what!

Best case senario is you get two independent tests to match and you can sleep a little better. I go through it all the time at work. Between me and my business partner we own 5 wood moisture metres.... we pick the 2 that are the closest that day, for the record it isn't usually the same two lol

[Myka]

Buy a 100 gram digital scale for like $10. Make your own fluid. Done.

[calo247]

I feel like I'm currently opening the Pandora's box of calibration fluid :neutral:.

Thanks for the heads up, if I paid $25 for overpriced saltwater to nuke my tank I'm going to be rather frustrated...

Anyway to calibrate my calibration fluid without buying more calibration fluid?!

you can make your own using rodi water and table salt. Randy Homes-Farley has a good article with a recipe.

i am going to make a batch and buy some of the pinpoint fluid, which from my research seems to be the most reliable fluid.

[Brunz]

....then you have to wonder of the purity of the solution you make based on the salt....

maybe I am just a paranoid lunatic :)

Actually I made up a test solution tonight using the most rudimentary equipment (vetinary syringe and a teaspoon) and well that came out at 35ppt so I'm just going to assume my refractometer is close enough and carry on. I did however begin to wonder because of this thread so thank you thread :D

[calo247]

thats why you use table salt, it is pure NaCl, and the density does not change, so if you weigh it you should be good to go