Nopox has magnesium?

[WrasseyReefer]

Hi everyone, I was noticing my magnesium (tested by trident and verified by salifert and Red Sea) has gone up on multiple occasions without any dosing of magnesium reagent. I decided to test the two other things I’m dosing (besides alk and calc) to see if they might be contributing some mag. I tested my neophos and my nopox. Neophos came back negative for magnesium. I don’t know if this is a real result or not, but nopox came back off the charts with magnesium. Salifert titration maxes out at 1500, and it didn’t change from pink to blue after I added the whole 1 ml of reagent, indicating that nopox has 1500+ magnesium. Thoughts? Could nopox dosing be contributing a small amount of magnesium to my tank? It takes a lot of magnesium reagent to increase it in a tank, and I only dose around 6 ml? of nopox per day, so it’s not much. The increases I’m seeing aren’t huge either, maybe 10-15. It could be testing error. But I’m curious about nopox testing positive for magnesium.

 

[gbroadbridge]

Nopox does not contain any Magnesium.

How were you testing?
You can't simply test Nopox for Mg as the test kits are designed to test salt water only.