is this heat stress? or a major deficency? plase please pease help!

Hey all, I've never see n this before, and have yet to find any pics of the same thing... I've got mini leaves on top in the new growth area looking slightly retarted/stunted with major drooping. Any help in identifying my probelm & i would be eternally greatful for. Thanks in advance for the help!
Ps: this is wk 1 of flower!!!

You have some sort of severe nutrient imbalance.
It could be one or a combo of so many things!
Please tell everything in exhaustive detail.
Strain? Lights? Temps? Humidity? medium? Nutrients (type and amounts and ... )? pH? Other stuff?
cn

Im using some additives on top of my "Ready for flower" nutes with the atami line. In addition to the recommended atami nutes (Except the root boost) Im using voodoo juice, and a lil soul synthetics amino acids, and a tiny ammount of superthrive. There is a possibility my ph fluxed for 2 days but I changed the res yesterday and added my the sames nutes. Should I consider poppin them back to veg cycle to recover?

What water? What ppm before and after compounding nutes? What sort of hydro? Some questions from above are also unanswered. The more you say, the better the likelihood that I or someone wiser might be able to say "aha!". cn

water is ro+di changed weekly. dont have a ppm meter, but i dose on the low side of the recommended. if says 2-3ml per L i dose at 2ml. per L Strain is dutch passion euforia, 4 600w lights, temps in mid to lower 80s, medium is rockwool, and my humidity is under control without a doubt

Well ... that knocks my major supposition out, which was ion competition from hard water.
I searched Google but was unable to find your base nutrient by name. I suspect you might have a serious Ca/Mg deficiency, but without identities and formulae and proportions of what you're using, I am purely guessing. cn

can i safely add some rock salt to the res? this is the nute line im using right here. http://www.atami.ca/america/nutrients/index.html

or should i foliar feed maybe? or should i dump the res and start again with just the atami stuff?

If by "rock salt" you mean sodium chloride ... NO! NNnoooooo! Both sodium and chloride ions are rather toxic to the Cannabis plant.

I would not add anything extraneous if you have no way of monitoring PPMs.

I clicked on your link, but it is confusing. I assume you are using B'cuzz hydro parts A and B.

Imo a ppm meter would be good to have right now. However ... I'll be honest - I am stumped. Your water is good; your change schedule is good; I have heard nothing bad about B'cuzz. Your temps are high-ish but not bad.

Final question: how are your roots? Are they thick and healthy? Is there any slime or odor or pathogen? What you have going on *might* be explained by a root problem. Can you tell I am guessing? cn

<edit> I do not recommend foliar feeding with ionics of any sort ... cannabis likes to spot-burn from hydro nutrient solutions.
Imo setting up a fresh reservoir using just the Atami is a good idea. Maybe perhaps.

~brainwave~ Aeration! What are your reservoir temps, and what steps are you taking to make sure the roots are well-aerated?

each pot has a air stone in the bottom to make sure the water does not become stale and drown the roots. the roots have been getting progressively worse and im scarde this might be the begining of root rot if not kept steady from here out! they are not brilliant white anymore but they are not rotting.... yet.

and i think i ment epsom salt. Cann, sounds like you know some chemestry beyond just ec levels and ph? is there a way of testing for exact chem levels?

UPDATE: the stem on the top cola all the way to the top, except the last node is a very obvious shade of purple..... is this particular of any specific deficency? high or low ph would cause the deficency?

my tops almost look like figure 10 on the following page. any chance this could be it?

www.onlinepot.org/grow/diagnosingplantgrowingproblems.htm