How Often To Re-Calibrate Refractometer?

[Reef Frog]

I often do a lot of wet skimming so salinity levels can change unless you're on top of it. So I choose to calibrate every time I use it. It's often spot on for a good while then it will be off a few points. Perhaps it's a temperature change - maybe the adjustment mechanism gets jiggled and changes things. Really dunno.

But since calibration costs & time spent are insignificant, I say "why not"? It's especially important when introducing new fish to low salinity water to a QT tank for example. I like to play it safe. To me is like taking a fuel sample to check for water in airplane gas tanks before I fly...or a hunter sighting in his rifle before going into the field (I no longer hunt)

Maybe this is obsessive but it seems logical to me. JMO.

 

[jason2459]

..
(I have also heard the red sea ones loose calibration quickly,..

My Red Sea refractometer lost calibration very quickly. Several el cheapo's I've played with over the years held calibration a lot better. I tossed the Red Sea refractometer in the trash.

YMMV

 

[downbeach]

I would do a 25 gal. WC every two weeks, and would check the refractometer using a seawater standard solution(35ppt/1.026), but would rarely need any adjustment.

 

[disc1]

I do this. When I make up water for a water change, I use my refrac to check the tank and then make the new water to match whatever the tank read. Usually it's pretty close and I'm confident that the tank's salinity is pretty close. If I see a reading that looks off by enough to make me question anything, then I recalibrate the refrac.

 

[thelawnwrangler]

Every Red Sea I've ever came across his horrible about calibration

lol this - I end up calibrating it with calibration fluid multiple times every water change until I am comfortable about the reading.

 

[BigEZ77]

lol this - I end up calibrating it with calibration fluid multiple times every water change until I am comfortable about the reading.

Is yours a red sea as well?

 

[Bent]

Is that you Cloak?

Dude I thought the same exact thing.

 

[PilotMaximus]

I have had the $39 BRS one for well over a year and calibrated it once after about 7 months and it wasn't even off. Just checked again at bout the 18 month old mark and required no adjustment. I do keep it stored away from my kids reach (they are cool looking) in a cool dry place with the little silica pack it came with. That may help.

 

[homer1475]

Mine is odd.

For the first year and a half I checked it every time I used it, never needed adjustment, but recently it needs to be adjusted every time I use it. No idea why and I haven't changed how or where I store it. So for me now I check it every time I use it.

 

[thelawnwrangler]

Is yours a red sea as well?

yeah it is a red sea

any bump and it is off I found. I checked my tank the other day and it was 1.030- I had an heart attack, re calibrate and I was fine high side of 1.026 which is a hair higher than I want it

 

[BigEZ77]

it was 1.030- I had an heart attack

lol

 

[thelawnwrangler]

I don't think it is a bad instrument- just needs calibration. The fluctuation makes me uneasy though.

 

[PilotMaximus]

One thing I havent tried was to check my refractometer against my hydrometer. I'll have to do that next chance I get.

 

[CStrickland]

Dude I thought the same exact thing.

Helen Keller sent me a pm, she was wondering too :dance::dance:

 

[spicytofu]

I have had bad luck with the refractometers. It find them useless.

I calibrated using 1.026/35ppt solution at 68 F. Then I took water out of my tank and cooled it to 68F. Adjusted the water sample until I got 1.026. Next, warmed refractometer and water sample to 77F (honestly it is not easy to maintain a 68F house during the summer)

My ATC refractometer should read 1.026 factoring in the 77F. NOPE, it shows my SG is at 1.028/1.029. Then I used the cal solution and also showed a similar increase (though not the same as the water sample)

I am done refrac and hydros. Went in for a conductivity meter. Costs like 4x more but I feel safer with it.