The point I was really trying to make in my last post but left out (lol) is that containerized plants are critical in the proper ratios of nutes because the rootball is in such a confined space, ANY little imbalance will throw off the balance and cause a deficiency and it doesn't take too much of any one substance to do this.
This, compounded with the fact that a rootbound plant cannot physically take in nutes causes a situation where if the nutes are not perfect every time a deficiency will occur.
I think if ya have enough soil it has to be forgiving to some imbalances. Look at my case, it might not all be lime in my water, but it's somethin, and that somethin is in it every time I water. Yet I don't have problems? I repot well before they get rootbound though. But even Martin's plants here had to be purty well rootbound before they showed signs of deficiencies..... I dig what yer saying about no tap water starting at 0 and what is in it should be taken in to account for the overall balance of the nutes. But it seems like a poke in the dark trying to counter it with other nutes though, how do ya know enough is enough? If yer water is that bad that it keeps causing imbalances and deficiencies, it's time for RO. I do know a feller can go a long way jus by transplanting sooner and having a buffer though.
Yer second paragraph is what I've been trying to say the whole thread.
10K... Did ya know humates are great on a cracker too? ( wait......what?! ) lol
Take care yall.... . BC