Spots on leaves, tacoing and burned tips

I have this white powdery looking stuff on my Kali Mist leaves. Not a lot but definitely getting more in the kart 24 hours. What is it?
also the tips on a few plants are tacoing and look somewhat burned.
Lastly, first time I’ve grown Jack Herer and Critical Kush. Are these crazy huge leaves common? They are completely blocking light to the new growth.

Big leaves yep. Definitely got a touch of nute burn maybe starting to OD on nitrogen. Water your feeds down a bit for a week she’ll come right

Darkoh69 said:

Big leaves yep. Definitely got a touch of nute burn maybe starting to OD on nitrogen. Water your feeds down a bit for a week she’ll come right

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I haven’t been feeding them anything except once so far three days ago. Tiger bloom

I'm new to this but I have a plant in week 5 of flowering and my leaves did the same thing I figured it was a calcium disorder I gave it cal/mag supplement and plain puer water with no nutrients for a week it seamed to solve my problems mine is growing like crazy buds are getting big fast