Cal mag - 1 teaspoon per gallon
Nectar - 1-2 teaspoons per gallon I used 1.5 teaspoons
Okay I'm back with some numbers. Let me preface this by saying I work with different ratios than most of the nute brands out there, running as close as I can to 5-1-5 in veg and 5-1-6 in flower
So this is my (and only my) analysis of what's happening:
Based on the week 4 feed chart you posted (
clearer image here) plus the 1tsp of calimagic and the 1.5tsp of Nectar, this looks like what you're feeding (in ml/gal):
Which means this is what the plant is getting:
That looks like a lot more Ca than needed to me. As seen in
Mulder's chart (source), calcium locks out magnesium, which could be why the plant is looking Mg deficient.
If it were my plant, I would drop the Nectar completely, add epsom salts (in grams), and change those feed numbers to the following (in ml/gal):
which puts you at these numbers:
You can see that Ca has dropped from 155ppm to 99, which is much more inline with how I recommend running.
A quick tap-water flush (2x the pot size should do it) followed almost immediately (after the dripping stops) by feeding with the new numbers would be the way I would go.
DISCLAIMER: If you were to post your question in the FAQ thread I linked to earlier, you will get a wide range of suggestions that will differ from mine. One or more of those might work as well, so this is not a my-way-or-the-highway recommendation. There is more than one right way to grow cannabis.