How Often To Re-Calibrate Refractometer?

BigEZ77

BigEZ77

Member
I realize I haven't done this in many months. Is this something I should do on a regular basis?

Thanks,
 
Its a red sea. Seems like its on, i.e. if my sg creeps up to 1.027, I put a little less salt in my next WC and it shows its come back down a bit.
 
FWIW I use one of those cheap floating glass hydrometers. No calibration needed as long a the temperature is between a certain level.. With all these threads pushing refractometers though, I'm starting to think how many of you are legit? ;)
 
Last edited:
I use the same bucket and salt-scooper to mix my saltwater, so I can usually just eyeball how much salt to add to a full bucket of RODI to get 1.025. I will still verify it with a refractometer though. If the reading is not between 1.024-6, then I recheck calibration to be sure.
 
fijisrfr said:
Every time I use it!


Sent from my iPhone using Tapatalk
Click to expand...

Just out of curiosity, do you think the odds are with you? These corals/fish/invertebrates might not be as delicate as one might think. "Off" could be just be good enough in the right hands... (not a refractometer) ;)
 
Last edited:
Animagus said:
FWIW I use one of those cheap floating glass hydrometers. No calibration needed as long a the temperature is between a certain level.. With all these threads pushing refractometers though, I'm starting to think how many of you are legit? ;)
Click to expand...

Is that you Cloak?
 
I calibrated my swing arm hydrometer once about 5 years ago against a just calibrated refractometer. Then I added a label that says "reads low by 0.004". Now, 5 years later it's still exactly the same. I compared it to a freshly calibrated refractometer every few months for a year or more, then twice a year for a couple years, now I do it once a year just for fun. Refractometers are just not worth the hassle IMHO.
 
I have a Red Sea also, and I notice I have to calibrate every time before I use it. I notice it changes depending on the temp inside the of my house.
 
Animagus said:
Just out of curiosity, do you think the odds are with you? These corals/fish/invertebrates might not be as delicate as one might think. "Off" could be just be good enough in the right hands... (not a refractometer) ;)
Click to expand...


I don't agonize over it. Check it before my weekly water change.


Sent from my iPhone using Tapatalk
 
I have a milwaukee digital and I haven't calibrated it for a while and it stays accurate. It's nice because it doesn't need a solution to calibrate, just ro or distilled water.
 
Hm. My cheapo Amazon.com refractometer was dead on when I purchased it 8 months ago, and hasn't needed any adjustment to this day. I verify it with RO/DI water every time I do a water change, and have checked it against my hydrometer as well. Weird to hear that this isn't the norm. Guess I got lucky on this one.
 
Things can drift. Knocking the refractometer over time will most definitely do it. But even if it's not physically knocked up through the use of the ATC mechanism will slowly over time cause the refractometer to need calibration again.

If using an el cheapo refractometer it's most likely not a seawater refractometer and should not be calibrated with RO/DI or distilled water even though the instructions say to do so. This article explains why better and much more thoroughly then I can.

Refractometers and Salinity Measurement
http://reefkeeping.com/issues/2006-12/rhf/

Those non-seawater refractometers will work just fine as long as you are not calibrating to 1.000 but calibrating to something like 1.0264/35ppt.


Even if it is a seawater refractometer I would still suggest using a standard solution that is as close to the end point you are trying to test for. i.e. 35ppt

I just posted this up on using store bought standards and possible problems with them.

Does your calibration solution need calibrated?
http://www.reefcentral.com/forums/showthread.php?t=2583418
 
I also posted this elsewhere that may be relevant as this applies to refractometers, hydrometers, probes, etc.

Consistency is key. If you have established a reasonable calibration protocol and fairly accurate method to determine salinity and stick with it you will be fine. If you believe you are reading 34-35ppt and maintain that level you should be just fine.

Corals can be found at various salinity levels. Salinity levels can change seasonally to daily. 35ppt is the canonical surface level average and a good number to set as the baseline to measure for. If you are not precisely there you should still be just fine.
 
BigEZ77 said:
Its a red sea. Seems like its on, i.e. if my sg creeps up to 1.027, I put a little less salt in my next WC and it shows its come back down a bit.
Click to expand...

It will always show the rise and fall of salinity, it is about 35PPT not actually being 34 or 36.

It only takes a second so I check the calibration every couple weeks, I have to adjust it 3-4 times a year.
(I have also heard the red sea ones loose calibration quickly, I am not sure as mine came from BRS)
 
You must log in or register to reply here.

Similar threads

J
  • Question Question
refugium help
Replies
4
Views
264
wvned
wvned
R
Midas blenny missing
Replies
5
Views
205
griss
griss
E
Refractometer woes….what would you do?
Replies
12
Views
1K
jrill
J
B
Left Tank for a long time, now want to reboot
Replies
8
Views
233
SantaMonica
S
A
First SPS coral. Is this bleaching?
Replies
6
Views
439
apavlik2
A
Back
Top