Refractometer or Electronic Calibration from RODI ??

RGA · 05/05/2015, 01:12 PM

Hello, I am new to the hobby and starting a saltwater tank.

I have noticed that when mixing my saltwater, my new electronic tester with auto temp correction gives a reading of 2.9% at 20 degrees, but my refractometer is showing 1.030 !

I have checked the refractometer against my RODI water and it is testing at zero.

Am I reading the electronic one incorrectly, or not set it ?

Its a Tecpel 850

Do I need to go to the expense of some calibration fluid, you would think RODI water should be ok ?

Any help, much appreciated, as if I don't start off with the right salinity from day 1 , I am sure to fail !

JammyBirch · 05/05/2015, 03:32 PM

Quote:

Originally Posted by RGA

Hello, I am new to the hobby and starting a saltwater tank.

I have noticed that when mixing my saltwater, my new electronic tester with auto temp correction gives a reading of 2.9% at 20 degrees, but my refractometer is showing 1.030 !

I have checked the refractometer against my RODI water and it is testing at zero.

Am I reading the electronic one incorrectly, or not set it ?

Its a Tecpel 850

Do I need to go to the expense of some calibration fluid, you would think RODI water should be ok ?

Any help, much appreciated, as if I don't start off with the right salinity from day 1 , I am sure to fail !

Rodi is not a good calibration for a refractometer. The calibration fluid is $3, if that's expensive sell the tank...this is not the hobby for you.

What are the units on the electronic meter? Sounds like something is way off, 1.030 should be 40%, 2.9% isn't even close.

Get the calibration fluid it will never give you false data.

gone fishin · 05/05/2015, 03:41 PM

I do not have any experience with the Tecpel but, one should calibrate a refractometer with calibration fluid periodically. Good luck just my 2 cents worth.

kmbyrnes · 05/05/2015, 06:19 PM

Quote:

Originally Posted by JammyBirch

What are the units on the electronic meter? Sounds like something is way off, 1.030 should be 40%, 2.9% isn't even close.

I'm confused by this answer, how do you arrive at 40% for 1.030?
2.9% is so close to .030 that it is within error margins of our hobby grade equipment.
Please explain.

disc1 · 05/05/2015, 08:18 PM

Quote:

Originally Posted by kmbyrnes

I'm confused by this answer, how do you arrive at 40% for 1.030?
2.9% is so close to .030 that it is within error margins of our hobby grade equipment.
Please explain.

I believe he meant 40ppt, which is 4.0%.

kmbyrnes · 05/06/2015, 05:41 AM

Makes sense now.
Thanks for clarifying.

JammyBirch · 05/06/2015, 07:41 AM

i looked at my refractometer 4% is 1.030 on the gauge i believe. The gauge i have has SG on one side and brix percent on the other. Must have missed the decimal. I need to check this again now since i never use the % scale...sorry for any confusion.

RGA · 05/06/2015, 02:16 PM

Thanks for the reply everyone.

Yes, calibration fluid is the way forward, as the readings are way off on both, unless the salinity meter is reading 2.9% meaning 1.029. Unfortunately, not clear in manual, making me assume 29 ppt, and that makes more sense.

Thought the RODI would be sufficient, but having read more on this subject, I can see that is not always the case.

homer1475 · 05/06/2015, 03:04 PM

I originally used RO/DI to calibrate(the instructions even say to use RO/DI). When I finally got some calibration fluid, it was off by .002 to .004. I only use calibration fluid now.

kmbyrnes · 05/06/2015, 06:27 PM

JammyBirch, Thanks for clearing that up. My mistake as well confusing 1.030 SG as 2.9%.
Too many names for the same salinity level.
Just one more way to confuse newcomers ( and some mot so new )

05/05/2015, 01:12 PM	#1
RGA Registered Member Join Date: May 2015 Location: Preston, UK Posts: 23	Refractometer or Electronic Calibration from RODI ?? Hello, I am new to the hobby and starting a saltwater tank. I have noticed that when mixing my saltwater, my new electronic tester with auto temp correction gives a reading of 2.9% at 20 degrees, but my refractometer is showing 1.030 ! I have checked the refractometer against my RODI water and it is testing at zero. Am I reading the electronic one incorrectly, or not set it ? Its a Tecpel 850 Do I need to go to the expense of some calibration fluid, you would think RODI water should be ok ? Any help, much appreciated, as if I don't start off with the right salinity from day 1 , I am sure to fail ! Last edited by RGA; 05/05/2015 at 01:28 PM.

05/05/2015, 03:41 PM	#3
gone fishin Registered Member Join Date: Jul 2011 Location: Wyocena Wi Posts: 6,936	I do not have any experience with the Tecpel but, one should calibrate a refractometer with calibration fluid periodically. Good luck just my 2 cents worth. __________________ Tony Current Tank Info: 180gal DT, BM NAC77 skimmer,3 Maxspect razors, Maxspect Gyre 150, 30g QT

05/06/2015, 05:41 AM	#6
kmbyrnes Registered Member Join Date: Aug 2013 Location: Mesa AZ Posts: 2,055	Makes sense now. Thanks for clarifying. __________________ 125g Mixed Reef 5/26/2015; 350 Butterfly Dominated FOWLR 11/26/2015 - 11/17/20217 & 07/31/18 to ??? ; 100g Mixed Reef 11/16/2013 to 06/16/2017 Current Tank Info: Too small

05/06/2015, 07:41 AM	#7
JammyBirch Aquaria Engineering Join Date: Mar 2014 Location: Elkland, PA Posts: 1,182	i looked at my refractometer 4% is 1.030 on the gauge i believe. The gauge i have has SG on one side and brix percent on the other. Must have missed the decimal. I need to check this again now since i never use the % scale...sorry for any confusion. __________________ 25g cube, split 10g sump with refugium, Jebao RW4, reefbreeder value Livestock adds: Osc Clowns, Royal Gramma, Pygmy Cherub Angel, Skunk Cleaner Shrimp, Serpent Brittle Star Current Tank Info: 25 gallon cube

05/06/2015, 03:04 PM	#9
homer1475 Registered Member Join Date: Mar 2015 Location: Upstate NY Posts: 5,313	I originally used RO/DI to calibrate(the instructions even say to use RO/DI). When I finally got some calibration fluid, it was off by .002 to .004. I only use calibration fluid now. __________________ 80G SCA Build: http://reefcentral.com/forums/showthread.php?t=2560256 Originally posted by der_wille_zur_macht: "He's just taking his lunch to work"

05/06/2015, 02:16 PM	#8
RGA Registered Member Join Date: May 2015 Location: Preston, UK Posts: 23	Thanks for the reply everyone. Yes, calibration fluid is the way forward, as the readings are way off on both, unless the salinity meter is reading 2.9% meaning 1.029. Unfortunately, not clear in manual, making me assume 29 ppt, and that makes more sense. Thought the RODI would be sufficient, but having read more on this subject, I can see that is not always the case.

05/06/2015, 06:27 PM	#10
kmbyrnes Registered Member Join Date: Aug 2013 Location: Mesa AZ Posts: 2,055	JammyBirch, Thanks for clearing that up. My mistake as well confusing 1.030 SG as 2.9%. Too many names for the same salinity level. Just one more way to confuse newcomers ( and some mot so new ) __________________ 125g Mixed Reef 5/26/2015; 350 Butterfly Dominated FOWLR 11/26/2015 - 11/17/20217 & 07/31/18 to ??? ; 100g Mixed Reef 11/16/2013 to 06/16/2017 Current Tank Info: Too small