My refractometer is way off when testing with Pinpoint 53mS calibration fluid - Page 2

sjm817 · #26 10/19/2006, 12:43 PM

FWIW, I went to the LFS with my refractometer. I have it calibrated to 1.026 with the Pinpoint solution. They tested it and their own (not the same model) with new SW. Both read 1.024.

Randy Holmes-Farley · #27 10/19/2006, 12:45 PM

If you read pure fresh water with it calibrated as is, what do you get?

sjm817 · #28 10/19/2006, 12:48 PM

Its off the bottom of the scale like -.004 or so.

Billybeau1 · #29 10/19/2006, 01:58 PM

Just like mine.

And everyone thought I was crazy

sjm817 · #30 10/19/2006, 02:19 PM

I still wish I could get a "firm" confirmation of using the Pinpoint 53mS for refractometer calibration before I go increasing my SG. So far, I have no hard evidence that it isn't applicable.

Lou Dell from ATI emailed me and said it works, but Randy wants to double check to be sure.

My refractometer calibrated with this solution reads the same as the one the LFS uses.

But...still want the OK from this board to be sure!

Randy Holmes-Farley · #31 10/19/2006, 03:13 PM

So far, I have no hard evidence that it isn't applicable.

I'm waiting for Lou Dell of American Marine to respond further. Even if you want to adjust it, you'd want to do it slowly.

You can make my DIY in the meanwhile if you want another check:

Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm

sjm817 · #32 10/20/2006, 03:09 PM

No update from Lou?

Randy Holmes-Farley · #33 10/20/2006, 03:13 PM

He may have replied to me at work but I didn't go to work today. I'll try to access emails later.

sjm817 · #34 10/21/2006, 09:35 AM

Thnx again. LMK if you get a reply.

Randy Holmes-Farley · #35 10/21/2006, 12:12 PM

OK, Lou has assured me that his standard looks fairly close to seawater (which is not always true or even necessary for a conductivity standard), and so can be used as a standard for a refractometer. So I'd believe it.

sjm817 · #36 10/21/2006, 12:36 PM

Awesome!

Thanks a bunch for the follow up. Hopefully this may help other members. $3.50 for a bottle is a bargain.

Randy Holmes-Farley · #37 10/21/2006, 12:57 PM

Yes, that is nice and I may include a reference link to it in an upcoming article on refractometers.

Boomer · #38 10/21/2006, 12:59 PM

sjm817

Try it on a hydrometer.

Billybeau1 · #39 10/21/2006, 01:06 PM

I've just been compelled to buy a bottle of this solution and test it on mine.

Upcoming article on refracts ?

Outstanding. Cant wait.

Randy Holmes-Farley · #40 10/21/2006, 01:09 PM

Upcoming article on refracts ?

Outstanding. Cant wait.

Either can I, but that means that I actually have to write it.

sjm817 · #41 10/21/2006, 01:13 PM

Quote:

Originally posted by Boomer
sjm817

Try it on a hydrometer.

The Pinpoint solution or my tank water?
I dont have a hydrometer, although I can get one. There is not enough of the cal fluid to fill up one of those swing hydrometers.

Billybeau1 · #42 10/21/2006, 01:14 PM

Well good for you. It will definitly help the refractometer owners feel better about the accuracy of their instruments.

Maybe the manufacturers of the inexpensive ones will quit telling people to calibrate with ro or distilled because it is just not true.

Billybeau1 · #43 10/21/2006, 01:16 PM

Quote:

Originally posted by Boomer
sjm817

Try it on a hydrometer.

Boomer, I will buy enough to test it against my lab grade floating hydrometer and let you know.

Boomer · #44 10/21/2006, 01:19 PM

The Pinpoint solution.

OK, it was just a thought . We'll get someone to do it

sjm817 · #45 10/21/2006, 01:28 PM

This might explain why others using Reef Crystals say their salt mixes up @ 400+ ca and mine was always ~ 360.

Billybeau1 · #46 10/21/2006, 01:29 PM

sjm, where did you buy the 53 mS reference solution by pinpoint. The two places I usually buy from dont show it in their catalog.

sjm817 · #47 10/21/2006, 01:31 PM

From my favorite vendor
Premium Aquatics

Billybeau1 · #48 10/21/2006, 01:33 PM

Quote:

Originally posted by sjm817
This might explain why others using Reef Crystals say their salt mixes up @ 400+ ca and mine was always ~ 360.

No smj, that has to be another problem. My refract is calibrated just like you, verified by my lab grade floating hydrometer and my Reef Crystals at 1.026 measures 420 calcium.

sjm817 · #49 10/21/2006, 01:35 PM

I thought I was mixing my salt @ 1.025 - 1.026. In reality it was 1.021 - 1.022 which would also make the ca low right?

Billybeau1 · #50 10/21/2006, 01:38 PM

Thanks for the link, How big is one bottle of solution. (I'll need enough to fill my hydrometer tube.

On the other subject, what calcium test kit are you using ?

Yes a lower salinity means less salt in the water meaning less calcium.