Salt mix solidified

[Cory]

I just made a batch of IO and wanted to test that the alk and calcium were proper. I assumed if my refractometer was working properly at 35ppt the all should be 7dkh and the calcium 400ppm. Well upon testing I found the alk was 4.6dkh and the calcium 360ppm. I suspected the refractometer wasn't working but suspected calcium carbonate precipitate from moisture. So I tested potassium it read 390ppm. So I suspect it's at 35ppt or pretty close. Is this usable if I bump the alk and calcium back up? Or should I test magnesium too? What should istant ocean be at 35ppt for parameters?

 

[Randy Holmes-Farley Verified Community Expert]

Yes, bump up the alk. Calcium if you want. The alk of IO is usually closer to 11 or 12 dKH, not 7.

 

[Cory]

Thanks Randy! I was waiting part of the day for your reply haha. I'll boost it up. Really it should be at 11dkh? That's strange. Well the conductivity will be here Wednesday well see what it is to compare. Should I be concerned about anything else in the mix? Like magnesium? Also can you confirm potassium of IO?

 

[Randy Holmes-Farley Verified Community Expert]

New England Patriots were playing!

Potassium of IO is about 400 ppm at 35 ppt. Yes, the alk is that high. Magnesium won't deplete noticeably by precipitation.

Alk is the main concern. Calcium only drops a bit. Nothing else to worry about that you can measure. Not sure on trace elements like iron,

 

[Cory]

Ah a sports fan! I just got IO reef crystals. Have you heard what that mixes to at 35ppt?

 

[Randy Holmes-Farley Verified Community Expert]

IO should be roughly 350-400 ppm for calcium, about 400-420 ppm for potassium, 11-12 dKH for alkalinity, and magnesium about 1290 ppm.

 

[Cory]

Thanks. We are talking reef crystals?
Best Aquarium Reef Sea Salt | Instant Ocean

 

[Randy Holmes-Farley Verified Community Expert]

No, I was talking about normal IO.

Reef Crystals has a little more more calcium and magnesium in it to start. About the same alk and potassium, I believe.