I never heard of anyone adding mag to a ca
reactor. Aragonite is the ca
reactor media, which needs the low pH provided by the co2
to begin to disslove. Aragonite does have some mag in it, but I don't think enough to keep the mag levels where they should be (around 1400ppm). Mag dissolves in regular tank water. I would think it would be gone almost instantly from the ca
reactor, while a reactor full a media can take a year to dissolve.
The amount of co2
injected controls how fast the ca
, it makes no sense to add mag to a ca