Magnesium in Aragonite

I've decided to give up on PMDD and go with mega doses of K (10 - 20 ppm per
week), P and N as required. I'll still keep dribbling the Trace Elements
every week.

The one thing I'm not sure about is the Magnesium levels. The recommended
level is up to 10 ppm, but should I treat this like the Potassium (K) or
dribble it with the Trace Elements. I've got some Aragonite in my filter,
does this provide any appreciable Magnesium? The consensus seems to be to
treat Magnesium similar to Potassium and add lots. But how much risk is
there that the Calcium/Magnesium balance will become out of sync and bother
the plants?

TIA