hi ub,
I've read quite a few of your stickies and that copper hydroxide experiment you ran on drugs forum. Good stuff, you know your botany. Got a couple quick questions i would like you to answer.
I have some vanilla kush plants that are showing slight leaf burn because I believe they were over fertilized. I'm being told by some it is a magnesium deficiency and others it is a ph imbalance in the soil (causing lockout) b/c i added flour dolemite lime to correct ph of sunshine #4 mix.
What's really interesting is the slight browning only occurred on the first set of fan leaves coming off the second node 24 hrs after topping. There is one plant that was still developing it's sixth node, so it wasn't topped and it is the only one which is not showing the symptoms. Not scientific, but interesting. Do you think that after topping the redirection of starches and nutrients may caused the browning to be localized to the older growth? Just a theory. Love to know what ya think.
here is a link to the more info.:
https://www.rollitup.org/marijuana-plant-problems/334440-beginning-something-suspicious-need-help.html
oh yeah, my course of action so far has been to flush all containers. Also, the plants are 3 weeks old. Can salt buildup occur that quickly? They were repotted in 1 gallons about a week and half ago.