DIY apex conductivity csliv

[Miami Reef]

I tried calibrating my probe with this DIY (I made it multiple times) and it’s just not working.

Using Alex’s calibration did not give me tank readings of 25ppt nor 45ppt.

 

[Miami Reef]

I did everything right. As of now I hate conductivity. I really wanted to like it.

 

[Randy Holmes-Farley Verified Community Expert]

lol

I do not know anything about how the APEX is calibrated, but it must use a fluid. What fluid?

 

[Miami Reef]

lol

I do not know anything about how the APEX is calibrated, but it must use a fluid. What fluid?

 

[Randy Holmes-Farley Verified Community Expert]

Assuming that was made correctly and my standard was made correctly (which might be a concern without a good scale), they should read exactly the same at the same temperature.

 

[Miami Reef]

Assuming that was made correctly and my standard was made correctly (which might be a concern without a good scale), they should read exactly the same at the same temperature.

I will try it again.

The recipe states 182g freshwater (RODI) with 6.2g Morton iodized salt

This is my scale: “This scale has a thousandth of a gram accuracy (0.001g) so it is extremely precise.”


I will use 18.2g water to 0.62g salt. This should be good, right? I will float this in my sump to match temperature and I will make sure that temp correct is 2.2%.

 

[Miami Reef]

edit

 

[Miami Reef]

I calibrated it. Apex is showing 33.9 ppt and my Milwaukee is showing between 34-35. To me, it’s like 34.8

I trust my Milwaukee more at this point because the Apex read the DIY salinity solution as 34 right after calibrating.

I literally paid more for the regular Apex because of this salinity feature (another fail safe if ATO fails), so me not trusting it is kind of hurting me.

This probe is just not good IMO. I’m seeing quite a bit of other people with similar issues.

Edit: Apex is showing 34ppt.

Let me see if my Milwaukee decides to settle on 34 as well. If it does that will make my night.

 

[Randy Holmes-Farley Verified Community Expert]

There are a few issues with controllers and salinity. One is temperature and how it is corrected and where it is measured.

The controller must know the temp IN THE STANDARD, not elsewhere.

Second issue is adjustable temp corrections, which can even be turned off (bad idea, unless you are are willing to figure out how to correct it).

Regardless of calibration or temp corrections, my standard and the one you picture should read the same if they are at the same temp. If not, one or both has a problem.

 

[Miami Reef]

@Randy Holmes-Farley

Thank you! I used a different “lab grade” scale and calibrated my conductivity meter perfectly.

I didn’t realize my Milwaukee refractometer had a +/- 2 PSU/PPT. That’s insane.

My salinity is now stable at 34.9ppt! Thank you so much!!

 

[iquitreef]

Thats cook. Good to know thanks

 

[Randy Holmes-Farley Verified Community Expert]

@Randy Holmes-Farley

Thank you! I used a different “lab grade” scale and calibrated my conductivity meter perfectly.

I didn’t realize my Milwaukee refractometer had a +/- 2 PSU/PPT. That’s insane.

My salinity is now stable at 34.9ppt! Thank you so much!!

You're welcome.

Happy Reefing.