IPC Low Sodium?

[pseudorand]

My IPC test came back with Na of 8640.42 ppm, which they state as low (Hanna agrees). I've read the other thread, so I think this means:

• My salinity is lower than I think
• I need to re-calibrate my refractometer
• This is a common thing people learn from IPC tests

However, I'm not sure I understand why increasing my salinity is the solution. IPC is giving me sodium in ppm. The SG my refractometer measures represents all dissolved salts and I can only find conversions from SG to ppt (which, I suppose, is all salt ions rather than just Na).

My Cl is 18604.56 ppm, which IPC does not flag as out of range. That's lower than the Hanna article, but not nearly as much off as Na. If reef salt is mostly NaCl, why wouldn't they both be off equally? The Hanna article has the ideal Na/Cl ratio of 10,500 / 19000 = 0.55. Mine is 8641 / 18604 = 0.46. That's a very different ratio.

Also, I'm not just chasing number. Almost all my corals died in DT within a month and a half after doing fine in QT for 45 days. Even candy canes, a kenya tree and duncas (all supposedly forgiving) are doing poorly. Mushrooms, half my zoas and 3 types of euphyllia are doing well, but montis, favias, acans, cyphastrea all died.

IPC also has my iodine low at 0.01 ppm with 0.05 as their suggested value.

My questions:

• Were I to increase my salinity to normalize Na, wouldn't I just end up with high Cl?
• What could cause just Na but not Cl to be low? (I use Red Sea blue bucket)
• Are the low Na or low Iodine likely explanations for my coral deaths? If so, which seems more likely?

 

[pseudorand]

I don't have calibration solution, but I recalibrated my refractometer using RO/DI, and it was low rather than high. It read 1.025 before and now reads 1.027.

 

[Randy Holmes-Farley]

IMO, your corals are not dying due to "low salinity" or low sodium.

Which ICP company? Not all give equally reliable results, IMO.

If sodium is low for the actual salinity, then the only explanation is elevated magnesium, calcium and/or potassium.

If salinity is just low then raising it raises everything. What does the ICP company project the salinity to be?

The main negatively charged species in seawater are chloride and sulfate. The ratio in natural seawater is fixed, but varies a lot in reef tanks and salt mixes without apparent issues.

 

[pseudorand]

IMO, your corals are not dying due to "low salinity" or low sodium.

Which ICP company? Not all give equally reliable results, IMO.

If sodium is low for the actual salinity, then the only explanation is elevated magnesium, calcium and/or potassium.

If salinity is just low then raising it raises everything. What does the ICP company project the salinity to be?

The main negatively charged species in seawater are chloride and sulfate. The ratio in natural seawater is fixed, but varies a lot in reef tanks and salt mixes without apparent issues.

Icp-analysis.com. They don't give me salinity.

What are the other companies?

 

[Randy Holmes-Farley]

Icp-analysis.com. They don't give me salinity.

What are the other companies?

Triton, Oceamo and ATI are likely good choices.

 

[pseudorand]

So in addition to the ICP-Analysis result I got on 3/11, I got both a Triton and ATI on 4/14. Water samples were taken at exactly the same time. They all say I have low Iodine and high Tin.

I've been dosing Iodine and my non-dead corals do seem to be doing better. My Idaho Grape monty, which I had written off as dead, also seems to have parts coming back to life.

No idea where the Tin came from, but given the consistency, it seems like the possible cause. Anyone have ideas on either how to identify the source or how to remove it (assuming it was a one-time contamination that I just have to get rid of.)


* ATI
* Triton
* ICP-Analysis (Below

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