Tbh.
I think a transplant and i little lime is all they need. (id personally add a little Epsom salts, for the hell of it too)
Id be using gypsum myself. Because your soil ph is in range. Gypsum will keep it there.
Check ph of your new soil.
If ph is lower than about 6.5. Use some lime. If ph is 6.5 or so, just use gypsum. The calcium in the lime, and magnesium in the Epsom salts will buffer your ph. So it doesn't fall.
Then transplant.
Water them in.
Done.
Anything "synthetic" sucks ass, if you're using organic soil.
You also must have a lot of drainage, and aeration in your soil, to dry in two days.
Growing cannabis indoors, in soil. Is no different at all, to pot plants outside.
Also these -
Read what we are telling you!
You'll find every soil grower to come, to this thread, has told you exactly the same things.
That is my advice.
