There's a significant thread on here about part C.
Post in thread 'Clarity on Tropic Marin Part C' https://www.reef2reef.com/threads/clarity-on-tropic-marin-part-c.572262/post-8544200
Yes. I’ve read it.
I still question why TM isn’t more upfront about the ingredients. Why just list Mg and K and then even tell you the recommended ranges to keep Mg and K with Part C?
If you look at the instructions on the Balling method they state what Part A and B are and recommend levels for alkalinity and calcium. Then under Part C they only list Mg and K (and their concentrations) and then recommend levels for Mg and K.
Seems very odd they don’t specify there are other elements. And if Part C is not meant to maintain Mg and K, why list the concentration and recommended levels of each?
I dosed Part C in my tank at a level lower than TM recommended and never had to dose Mg even when I wasn’t doing weekly water changes. So it clearly can supplement element usage. At least for Mg and K in my experience.
But this is all off topic to the thread at hand. I just wanted to point out something.