If the reactor is working well, you won't need any other calcium and alkalinity supplements. Steve did not have his reactor adjusted correctly the few times I checked it. (I built it) Also, he does have an extremely high calcium demand, and given his schedule, I suppose it's easier for him to just dose the b-ionic than mess with the reactor. But, in general, a well designed, well adjusted (critical) calcium reactor is going to keep up with any aquarium's calcium and alkalinity needs. It's a good idea to drip kalk as well as run a reactor; they work together.