Neptune Aquatics

Salinity has been OFF???

NickRoseSN1985

NickRoseSN1985

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So today I decided to get new calibration fluid for my refractometer which I use to compare to my Hanna Salinity. Well something is wrong. The refractometer is showing 40ppt but the Hanna Salinity is showing 35.6ppt. I calibrated the Hanna three times and its showing that its calibrated(I float the pouch and checker so there the same temp). I even went back to the LFS(Ultimate Aquarium) and had them test the tank water and its showing 40ppt. Came back home and did my normal testing of the new salt mix and tank water since its water change day. New salt is 35.3ppt(Hanna)40ppt(refractometer), 8Alk, 430Ca, 1400Mag, Main tank, 35.6ppt(Hanna)40ppt(refractometer), 7.7Alk, 485Ca, 1380Mag. If the refractometer is correct I dont know how long the tanks have been at 40ppt, it could be a year, half year or less. All the corals are doing great, the SPS are growing like crazy.

So what do I do. I might contact Pete Smith at Hanna to see if it could be the checker.
 
It’s just so confusing. Now that I know my tank is at possibly 40ppt I would think that the new corals I got from @ofzakaria would have died going from his 35ppt to my 40ppt. I’ll contact some of the San Mateo reefers to test my water.
 
What type of salt?

Did you calibrate each with different solutions? Hanna is a conductivity probe, you normally can't use its calibration solution to calibrate a refractometer.
 
Vhuang168 said:
What type of salt?

Did you calibrate each with different solutions? Hanna is a conductivity probe, you normally can't use its calibration solution to calibrate a refractometer.
Click to expand...
I use Salinity for my salt mix.
I used Hannas calibration fluid for Hanna Salinity checker and Brightwell Calibration fluid for the refractometer. The refractometer is a Opticon Series FG100sa

I just went to a fellow reefer that also has a Hanna and he calibrated his and it showed the same numbers that I got when I tested the salinity before going to his house.

This week I will find some others that have refractometers.
 
So here is the update on the Salinity. Like I said I had Ultimate Aquarium test and they got 40ppt with their refractometer. After that I have brought it down to 39-38ppt. I had a local reefer that has a Hanna and his matched my Hanna. I also ordered 2 other calibration fluids and they matched the other calibration fluid for the refractometer. I just picked up a local reefers refractometer and his matches my refractometer.

It’s just odd that all my corals are doing great especially the new SPS. I would think that the SPS I got from Omar in December and February would have died going from his 35ppt tank to my 40ppt tank. But all of his frags are incrusting. This is his Shag Priority. First photo is from February 27th and the second is yesterday. Wouldn’t this SPS have died. Even if I go slowly I would hate to lower the salinity and lose these frags.


I guess both the refractometer and Hanna are within there accuracy range. Both of them have a +/-1ppt. So right now the refractometer is testing 38-39 and the Hanna is 36.5.

I like to go slow(some of you might say I can go faster). So I was thinking bringing it down 1ppt and wait a month or more and then do another point and so forth until I get to 35ppt.

February 27th
022B2374-18FB-43EE-9919-A5A70AD7E047.jpeg

April 8th
20BD4688-E817-4AF2-BB43-B18F43A805EA.jpeg
 
No reason to go fast. I’ve never experimented with taking frags from 35-40 quickly, but I’m not that surprised they made it. Especially since they were healthy and not newly cut when you got them.
 
The refractometer you have looks to be scaled for 20deg C.
40ppt is 1.030sg. So if you follow the general shape of the lines, you'll see that at 25deg C (or 77deg F), that equates to about 1.027sg.

Screen Shot 2021-04-10 at 2.14.10 PM.png
 
Do you have the link to that graph? I thought since it has ATC it doesn’t matter what temperature you have. Also the refractometer that I borrowed yesterday is a BRS unit.
 
So the salinity debate is back on. I sent ATI-ICP test out for both of my tanks. The salinity came back at 33ppt while my refractometer reads 35ppt. I have attached my results of both tanks. Also I emailed ATI about this and they sent a photo of them testing the salinity. Would any of the elements indicate that the conductivity devices are the ones showing the true salinity unlike the refractometer. The sodium shows -199.7 mg/l and -266.4 mg/l.

//lab.atiaquaristik.com/share/e16a0e89c5ee321c01b2
//lab.atiaquaristik.com/share/626576717333e0129886
7E4AF8C9-9155-4A2F-A729-AFBDE5A9F05B.jpeg
 
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