Salinity

[CodyF.]

What’s the “trusted” way to measure salinity? Currently, I’m using a refractometer but just received an IPC and my PSU is high. I’m using the recipe Randy posted, and really like it. But my salinity is 38 as per my ICP. Which is more than likely contributing to some STN I’m currently experiencing. I was using a calibration fluid but that had my salinity very low.

Admittedly, when I calibrate the refractometer I don’t really adjust to temperature. I made a litter and that’s kinda hard to temperature acclimate.

Do you guys have a better way? Guess I could temperature adjust the solution in a smaller container. But, I’m kinda tired of the errors and looking for something more precise.

 

[Randy Holmes-Farley]

What refractometer?

What did you use to calibrate it with that 1 liter of solution? My recipe? It should not need any temp correction with most refractomerters.

I prefer conductivity meters, but if you want an inexpensive device that, assuming it was made correctly, cannot be miscalibrated, the Tropic Marin hydrometer is a good bet. It's a little clunky to use in some scenarios, but folks like it.

 

[CodyF.]

What refractometer?

What did you use to calibrate it with that 1 liter of solution? My recipe? It should not need any temp correction with most refractomerters.

I prefer conductivity meters, but if you want an inexpensive device that, assuming it was made correctly, cannot be miscalibrated, the Tropic Marin hydrometer is a good bet. It's a little clunky to use in some scenarios, but folks like it.

Randy, it was your solution via the thread on here.

I think it’s an Amazon refractometer. Theres a possibility I made the solution wrong.

Does the conductive meter need calibration? If so, I’m assuming RO/Distilled water would be fine?

 

[Randy Holmes-Farley]

Randy, it was your solution via the thread on here.

I think it’s an Amazon refractometer. Theres a possibility I made the solution wrong.

Does the conductive meter need calibration? If so, I’m assuming RO/Distilled water would be fine?

Most conductivity meters need calibration, but it must be a salinity standard. Any conductivity meter that is not literally broken will read zero in ro/di, whether properly calibrated or not.

I used a conductivity meter (an Orion 128 with a 4 electrode probe) for decades. It could not be calibrated, and it also never varied, but any meter, and in fact, any salinity device we use, can and should be checked for accuracy.

 

[CodyF.]

Randy, it was your solution via the thread on here.

I think it’s an Amazon refractometer. Theres a possibility I made the solution wrong.

Does the conductive meter need calibration? If so, I’m assuming RO/Distilled water would be fine?

Most conductivity meters need calibration, but it must be a salinity standard. Any conductivity meter that is not literally broken will read zero in ro/di, whether properly calibrated or not.

I used a conductivity meter (an Orion 128 with a 4 electrode probe) for decades. It could not be calibrated, and it also never varied, but any meter, and in fact, any salinity device we use, can and should be checked for accuracy.

My refractometer could be broken-highly probable!! I appreciate your help.

I will look into a replacement. What’s your recommendation to take out the human error? Tropic Marin Hydrometer?

On another note, my iodine was high. I’m using AFR and Tropic Marin Pro-Reef. I’m low on a few things like Manganese. I don’t dose anything else outside of those two things, ammonia and two little fishes acro power.

Overall my water quality was 75. I’d like to dial in salinity and traces. Do you guys have an idea to why my iodine was off?

 

[rtparty]

Who did the ICP test? I wouldn't immediately assume they are "correct" and you are "incorrect"

 

[CodyF.]

Who did the ICP test? I wouldn't immediately assume they are "correct" and you are "incorrect"

ATI-OES.

 

[KStatefan]

Theres a possibility I made the solution wrong.

Make some more if you think it might be wrong.

 

[CodyF.]

Theres a possibility I made the solution wrong.

Make some more if you think it might be wrong.

Correct. That said, there is still a human factor. I’m looking for a way to take it out. Im very positive I made it correctly

 

[CodyF.]

Update, used regular distilled water at room temp to calibrate my refractometer and my tank salinity matched the ICP. This would explain why I’ve been loosing acros to STN.

So, clearly I messed something up when I made the solution. Not sure how? But obviously I did.