got ethical husbandry?

Salinity Variation

pixelpixi

pixelpixi

Guest
BARcard
Just for fun today I decided to test the salinity of the water all my frags came in, just to get an idea of the variation in salinity between different peoples tanks. Here are the results. I was surprised there were as many running lower salinities.






uS

ppt

refract




#1

56.1

37.3

1.028




#2

54.7

36.2

1.027




#3

54.1

35.7

1.027




#4

51.4

33.7

1.025




#5

50.8

33.3

1.025




#6

49.1

32.1

1.024




#7

48.5

31.6

1.024




#8

48.3

31.5

1.024




#9

46.4

30.1

1.023
 
Eric: yes!

Bryan: I don't think I ended up with any of yours today.

The temperatures should have been the same, since they were all in the same conditions for hours. Regardless, the meter measures and compensates for temperature so it wouldn't matter anyway.
 
I got a question on salinity too.
I use a standard refractometer and decided to calibrate it with the fluid I got at the swap.
My last calibration was done about 6 months ago with a calibration fluid I got on eBay and a calibration fluid I use from Joe at Aquarium Collection.
They both matched and I have been usgin ever since.
Yesterday I put one I got from swap and it was way off... Like 2 to 3 ppt difference.
I went ahead and used the same one I originally used on my 1st calibration and the refractometer deviated just a tiny bit. Nothing significant.
I was under the impression they don't expire. Mine has been stored with no light at room temperature.
Which one should I trust?
Would anyone be able to confirm the one handed to us at the swap is correct??
The one I used was the old stock that had been relabeled.

Thanks.
 
I just recalibrated with the BAR standard, I had to bump up my refract 1.5ppt, I was using the Pinpoint before, but I trust Norm more than those guys :D

1.023 is still the lower part of the threshold and you can do fine with that IME, it's flirting with the higher end that has given me a problem in the past (above 1.027).
 
My understanding is that so long as they are stored properly cap tight and upright, they should be fine. However, if you are getting inconsistant readings I would double check before making any huge adjustments if your corals look fine.
 
We calibrate ours weekly (one that is used 24/7 as a monitor) and the hand units get it very use. Our PH testers get calibrated every use and monitors get done weekly.
 
It's not the calibration that I have problems with. It's standards with different values I'm having problems with.
I got 2 standards that give me different results.
 
newhobby said:
It's not the calibration that I have problems with. It's standards with different values I'm having problems with.
I got 2 standards that give me different results.
Click to expand...
worth noting that poor technique can make 2 testings of a single calibration solution, give two different results :)
Most people don't realize how much technique matters. Little details like properly pre-rinsing etc can make a huge difference (this coming from someone who taught several analytical chem labs)
 
I used the one I bought from eBay and the one from Aquatic Collection.
Maybe they are just not precisely done and I have been using an uncalibrated refractometer all this time.
Can I bring my refractometer to next meeting so you guys can take a look at it?
Thanks
 
You must log in or register to reply here.
Back
Top