Oops.. Remember to calibrate your refractometer

[Rakie]

So it's been like... A year, since I calibrated the thing.. My water was a perfect 1.026, nice and stable. I had wondered though, why things were looking okay, but they had looked better previously. I figured time heals all color, right?

Well, not when your salinity is actually 1.020 -- That's right. 1.020, a slip of 0.06 salinity in my refractometer.

So yeah... Big oops.

Luckily it wasn't a tank nuke. At 1.020, it definitely could have been. And odds are, my salinity has been low for the better part of 6+ months. So whats the silver lining? I still had decent growth and color... And Everything will improve -- So, that's cool.

Don't be too lazy to check things. You might go a year with low salinity, apparently. ;Dead

 

[dbl]

Great post and the Reefing PSA of the day!!!

 

[Bob Lauson]

Interestingly enough I sent a message water sample to aqua medic testing and got my results. In addition the parameters they said my salinity was 1.029! I was shocked. I ordered a new calibration fluid for my refractometer and it was off. I was using about a 5 year old calibration sample so there must be some sort of shelf life to the stuff.

 

[Jim Heenan]

Good advice.

 

[SashimiTurtle]

I just checked mine today when I was making salt, it had been a few weeks... right on 1.026. Good tip, something as simple as not calibrating our tools could possibly have a very bad outcome.

 

[Rakie]

Yep -- absolutely guys. In this hobby we tend to worry about the big things, and turn a blind eye to the little things. In my case, those little things can absolutely sneak up on you, and end up being big things themselves.

 

[Donovan Joannes]

I saw an online posting of freshwater grouper recently. I wonder whether we can have a freshwater reefs by slowly reducing the salinity over a year or two?.

Back to refractometer, yes I always double check the reading with a fresh NSW I collect every month when I was on the beach. And surprisingly it can be off by 0.002 on every initial test, plus/minus. And all water sample are on same room temperature including that ATC refractometer, so temperature effect should be near zero.

 

[DeepBlueSomething]

I agree there are two important reminders - calibrate your refractometers AND those calibration solution do have a shelf life. As said above, small seeming items that could have huge impacts!

 

[hockeyhead019]

Glad to hear you caught it and definitely a good PSA! I think more importantly than being off by .005 is the consistency. At least that's what I've noticed in my reef

It probably matters what you have in the tank too, I have pretty hardy corals and fish in my system right now lol

 

[Rakie]

Glad to hear you caught it and definitely a good PSA! I think more importantly than being off by .005 is the consistency. At least that's what I've noticed in my reef

It probably matters what you have in the tank too, I have pretty hardy corals and fish in my system right now lol

All I keep is SPS, and I have a high fish load. I would agree consistency matters more, but as far as a reef is concerned, 1.020 is basically fresh water haha

I agree there are two important reminders - calibrate your refractometers AND those calibration solution do have a shelf life. As said above, small seeming items that could have huge impacts!

Correct, and not to mention calibration fluid can also be a bad batch.