Thanks guys. I think I finally have this down. My parameters tonight were:
Ca 370
dkH 9.3
Mg 1200
pH 8.3
I will keep adding Ca to get as close to balance as I can, and since my Ca supplement contains some Mg, I will keep an eye on what it does before I start supplementing the Mg. Once I am in balance the Ca reactor will get restarted and we'll see how it goes.
You do not have to get to balance really and want a little extra ALk for other reactions, so 420 is fine. Use only something like Kent Turbo, Calcium Chloride. Raise it 20 ppm / day. I would raise the Magnesium first, which can be raised 100 ppm / day.
Finally! I am as close to balance as I am willing to push it.
Ca 415
dkH 8.3
Mg 1200
ph 8.23
I have kicked my Ca reactor back on, at a much lower flow than previously, and will adjust it to keep settings as steady as possible. Now just to get my Mg up to 1350.