Help, my refractometer isn't working

Marty · 03-11-2008, 06:14 PM

I bought the portable refractometer from that Doctor aquarium place in Wyoming and it's acting weird.

I calibrate it using their ro water and adjust the screw until it reads zero, then when I put my salt water on it the readings go below zero. How can I have less than zero salt? What am I doing wrong? :O)

bmshehan · 03-11-2008, 06:35 PM

Quote:

Originally Posted by Marty

I bought the portable refractometer from that Doctor aquarium place in Wyoming and it's acting weird.

I calibrate it using their ro water and adjust the screw until it reads zero, then when I put my salt water on it the readings go below zero. How can I have less than zero salt? What am I doing wrong? :O)

Make sure there are no bubbles under the glass, it needs to be solid water. Is your unit ATC (automatic temperature compensating)??? These are my best guesses!!! With mine I pull it out of the box drop water on it and I'm done! No problems at all, so I'm clueless if the above things don't help!

Marty · 03-11-2008, 06:47 PM

Yeah, it's temperature compensating, but the bottle of calibration water says "PINPOINT Salinity Monitor 53.0mS Calibration Fluid +-1% @77F/25C American marine Inc. The refractometer model number is RHS-10ATC. No bubbles either.

omard · 03-11-2008, 06:58 PM

Take down to LFS and have him check it out and calibrate for you.

bmshehan · 03-11-2008, 06:58 PM

I tried!!! See what any experts have to say... Meanwhile, have a friend test for you, if you don't have any buddies with a working refractometer maybe take a sample to your lfs and see what they have to say. you may have a defunct refractometer?

chuckdee · 03-11-2008, 07:03 PM

That's sounds really weird. Never heard of that before. All I can say is you're ok because Drs Foster & Smith have A++++ customer service. They'll send you a new one, no questions asked..

ReefSparky · 03-11-2008, 07:26 PM

Quote:

Originally Posted by Marty

53.0mS Calibration Fluid +-1% @77F/25C American marine Inc.

Marty, I'm not so sure this calibration fluid has no salinity to it. My best guess is that you're using a calibration fluid that contains more salt than sea water to calibrate your instrument to zero. Have your read the accompanying literature?

Do this: Boil a pot of water with a cover, and use the condensed water from the underside of the cover on the prism of the refractometer. That's distilled water.

For all intents and purposes, a refractometer can't "not work." It has no moving parts and uses only light and known refraction of salt to yield a reading.

Start with the distilled water, and I think your problem will be solved.

Good luck!

Marty · 03-11-2008, 07:38 PM

I am soooo dumb! I did a search of this calibration fluid and the one complaints was that there is no instructions. Turns out it has a salinity of 35 ppt. So you have to calibrate it to that. Did and sure enough my tank water is 1.022. Thank god for google. hehe Think I will try it calibrating to 0 and to the 35 and take an average. <shrug> couldn't hurt.

Thanks for the replies. :O) Karma to you..

ReefSparky · 03-11-2008, 07:44 PM

Use distilled water and calibrate it to zero. Don't knock yourself out. I don't care how "lab tested" that calibration fluid was at the factory. Although it's unlikely, that level can change and you'll never know it.

Distilled water is 0 everywhere.

bmshehan · 03-11-2008, 07:52 PM

WOW, learn something new every day!! I just calibrated mine with RO water and everything is great in refractoland!! Mine didn't come with any solutions either though, sounds like a waste of money for the company!