Firstly, I never quoted anyone... If you don't actually know what a 'quote' is then you need to go back to school. I gave anecdotal evidence I have heard in the canna community re purple strains and qualified this by saying it is what I have 'heard'. And I certainly never made out it was fact.
Funny how at the bottom of the post it says reply with quote and funny how what you said is now in quoted abreviated internet speech!lol! School, do me a favour!lol!
Secondly, how do you know they are not so called 'purple' strains... With names like, 'Black' or 'Blue Bull' I would say they likely have purple pheno types.
Again i dont but so often as you 'QUOTED' and others quote the same without the realisation that purple strains are but a small percentage of the strains grown here at rollitup and the rest of the world so chances are im more right than you here!
Thirdly, Any dummy knows if you keep any light in a 'sealed' wardrope, then 'eventually' heat will build up.... Fortunately this dude has enough sense to grow in a proper tent, im guessing with intake/outtake.
Not always, plenty new growers think that a simple desk or stand fan will cool the lights in a sealed drobe or tent, a centrifugal fan can seem like a big outlay cost wise and is seldom the last purchase made, the bigger the tent the larger the fan reguardless of the lights as you dont see a 4 inch fan moving the heat from at 5 meter by 5 meter grow. Again plenty to consider but lets just hope hes at least got a decnt inline or relative ventilation fan to exhaust and change the air.
Fourthly, You suggest 'fert imbalance', that just shows youre a newbie because the pics the O.P posted show zero evidence of this.
Everyone on this board is a newbie in some way or another, unwise of me not to consider a problem fert wise wether it be too much or too little or the wrong kind but simply put i wasnt going to put it down to being a purple strain or too cold, i find this too be by far too easy and quite often misunderstood answer to purple stems and petioles, calcium can play some part in it too as well as phosphorous and in some ways the two are interelated but then again all nutrients are.
You certainly dont find me calling anyone a newbie or dummie even if i seem to come across non symthetically on all my posts. Peace