Anyone know where to get Pinpoint refractometer calibration fluid or similar locally?

[Ebmorri]

Anyone know where to get Pinpoint refractometer calibration fluid or similar locally?

TIA

[asm481]

The Filter guys

[asm481]

sorry I didn't notice local!

[roadracn]

ummmm dont you just use distilled water?

[MyCatsDrool]

I'd try premier. I know they stock a LOT of calibration fluids. Talk to Travis, Dave or Will.

[rmougey]

Originally posted by roadracn
ummmm dont you just use distilled water?

It's always worked for me....... should read 1.000.

-Rob

[Zooid]

Originally posted by rmougey
It's always worked for me....... should read 1.000.

-Rob

yep. I always used RO/DI.

[Jagermeister]

Over on the chemistry forum the consensus is that refractometers should be calibrated with a solution that has a salinity close to that of natural sea water. A lot of people are finding out that even though they calibrated their refractometer with distilled water, when they tested a calibration fluid their measurements were way off.

I'm one of those people. I've been calibrating my refractometer with distilled water since I got it. After reading those posts, I recalibrated it with a calibrating solution. My refractometer was off by 0.005. My reef's actual salinity was 1.021 when I thought it was 1.026. Quite a big difference.

That being said, Randy has written an article detailing how to make your own calibration solution using distilled water and table salt.

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

[Left Coast DJ]

Pinpoint Salinity Calibration Fluid

[salthappy]

Neptunes carrys them

[roadracn]

called them today and they said they didnt...? Someone else have news about this?

[icantremember]

Make your own calibration solution like Jagermeister suggested. 1 level tsp of Morton's Table Salt to 161mL of distilled water. This will give you 1.026 or 35 ppt. It's not accurate to calibrate your refractometer with RO/DI water. Actually, once you are calibrated you will see that the RO/DI is actually closer to .096-.098 versus 1.000. Another reefer ordered the 53µS calibration solution for comparison and found that the DIY solution was identical to the Pinpoint calibration solution.

[roadracn]

and how do I get exactly 161 ML?

[Ebmorri]

I have made the solution, I just want to make 100% sure of everything. If you can test with the homemade solution then cross check with another solution I feel the results will be better. I measured everything out on a scale to make sure it was correct but the more "know" base points you have the better the results will be.

[LooseHip]

Oh yeah and for those who may be wondering, Erick tested a hydrometer with the DIY solution and it was dead on!

[icantremember]

Check out this thread -

http://archive.reefcentral.com/forum...readid=1283622

and how do I get exactly 161 ML?

I used a graduated cylinder the first time. Second time I used a 10mL syringe. Both solutions yielded the same results. The thread above also says you can use a 2L Coke bottle filled to the top with RO/DI and 1/4 cup + 1 tsp of Morton's. Supposedly the Coke bottles are the same and this formula yields the same 35 ppt solution.

[roadracn]

made the solution and mine was way off, .006-.007 going to recheck the measurement and try again to make sure