So there’s a difference between a deficiency and the plant not getting the optimum amount of something. So we might see no obvious deficianecy, but maybe the plant would be really enhanced by more of something, or a differnt balance. That’s not to say there’s been anything too out of whack here G! It’s looked wonderful alsome the whole time!
On the calcium thing... looking at the basis of the High Brix growing, it favours calcium in a balanced mineral ratio over other nutes. Not that the other nutes/components don’t count, just that calcium is the ‘engine’ of the plant. I’ve read about ideal cal:mag ratio being 6-9:1. I tried to implement this on my recent outdoor grow and I can definitely say, even with my making a few mistakes, that the stems were hella strong (I could not even bend the main stem of either of my main plants after harvest - not at all!). I can also vouch for the fact that none of them were hollow.