Refractometer woes, advice?

Hey all,

I bought this refractometer when I started reefing about 6 months ago.
Saltwater Aquarium Salinity & Specific Gravity Testing: Portable Refractometer

It's a very common one and I'm sure lots of you may have the same one. I've noticed that it has started to be waaaaay off and needs to be calibrated probably before almost every use. I use RO/DI water to calibrate to 0 and have never used anything else. The water is 0 TDS, tested with an HM meter.

I am considering buying a pinpoint digital salnity monitor because I feel this refracto isn't working properly. Is it normal to have to recalibrate so often? Can someone give me some input on a better quality meter they are using. I'm just very tired of having to re-calibrate so often & second guessing actual salinity.

Thanks!

 

Try calibrating with distilled water or calibration solution instead of RO.

 

the directions with mine said to calibrate to 1.0 with RO water.

 

really, hmmmm I haven't read the directions in a while, maybe that's the issue. I swore I've seen numerous things about peope calibrating to 0 with RO/DI water, no?

AM: I'm going to grab some distilled tonight also, I believe that's what I used for the initial calibration.

 

I purchased an inexpensive (($39.99) Refractometer from BRS in December. It came with a free bottle of Calibration Fluid and has worked great for me. I test the calibration every few times I use it with the calibration fluid and then with either RO or distilled water. As of yet, I have not had to recalibrate this refractometer. Good Luck.

 

Thx for the input John, do you calibrate to 0 with your RO water or 1? I know distilled is 0 def.

 

I also have to recalibrate every time I test salinity. It can be quite aggravating, its as if the calibration screw slowly over time slips. I calibrate mine to 0 using ro water.

 

FWIW I haven't had to calibrate mine since I got it in late 2008. I check it every few months and it stays on target...

 

I followed the instructions for mine, set to 0 with distilled water. After I got some calibration fluid I found it was off about .004! It read 1.026 with distilled and read 1.030 after using the fluid. I would recomend getting some calibration fluid.

TJ

 

I wish this were the case with mine. I am extremely careful with it and rinse it with ro water after every use. Time and time again mine has been off by a drastic number as if I slammed it into a wall and then tried to read it.