Strange levels in fresh IO...

[Velcro]

Made up a fresh batch of IO blue box. Used an entire 50gallon bag and mixed to 35ppt. Used a BRS refractometer calibrated to 35ppt with TLF accurasea solution.

I'm confused by the levels...
Alk: 9.5 dKH
Ca: 435
Mag: 1600ish

how is this possible lol

 

[Dr. Reef Verified Sponsor]

alk and cal is pretty much close to the avg. (cal 415, alk 10.5) but mag is high (avg 1320)

 

[Bpb]

I had a couple batches of plain IO with 1600+ ppm Mg as well. Probably 2-3 200 gallon mix boxes. The most recent one is back around 1450.

 

[Velcro]

Strange. Oh well, not that big of a deal since I just do like 1% AWC. I'll just have to dose less mag every week!

 

[Velcro]

Also, what volume of water are you guys getting for 1bag (50g) at 35 ppt? Mine is just over 40 gallons.

 

[Deedles]

I'd say that's similar to what I'm getting. I definitely have to add a bit more than the recommended amount to each gallon to get the appropriate salinity.

 

[Randy Holmes-Farley Verified Community Expert]

Some magnesium kits (notably Red Sea) also seem to be a problem, and if you are using that kit, I'd focus on test error before bad batch.

 

[Velcro]

Some magnesium kits (notably Red Sea) also seem to be a problem, and if you are using that kit, I'd focus on test error before bad batch.

I use the salifert exclusively. It has always been very close to what aquavitro salinity has listed on the bucket.

 

[JimWelsh]

I had a batch of IO that had high Mg like that a few years ago. I used Salifert, too, then. The bad batch of IO coincided with me getting a new Salifert Mg test kit, so I assumed the test kit was bad. The vendor gave me a replacement test kit, which also read high. Only then did I realize the problem was with the IO, not the kit.

 

[Bpb]

Yeah I’ve tried 3 different lot number Mg tests with all the same reading