Trying to manipulate the grow area I forgot to tur...

Rotting will be brownish black and slimy, this I think is possibly what you thought too, minor burning from fertilizers on the leaves. To me, your plant looks rather thirsty and the substrate rather dry too, give her a good drink to run off, she might just enjoy this and there is no need to fear over watering, too dry is much worse than slightly too moist. Besides, the coco coir and perlite will prevent any "water logging". Roots won't expand into dry areas, nor will nutrients be available. Aim to keep the substrate moist, from edge to edge and top to bottom. This is why watering to run off is important, otherwise you will have no idea how far the water has penetrated the pot. It can also help prevent nutrient/fertilizer salts from building up in the substrate. To have deficiency signs this early in life, would be unlikely in my opinion. Having 75% humidity for 8 hours will not cause a problem, it is far more humid during a rain storm which may last for days outdoors and this is where cannabis originates from after all. Cannabis is a remarkable resilient and tough plant. All the freaking out about one degree or the "having everything in perfectly exact conditions or you are doing something wrong" type of attitude, that is seemingly mandatory to some contributors, just causes stress and paranoia amongst new growers and I don't believe it is overly helpful to be so rigid when dispensing advice. Growing your own should be a fun hobby that is relaxing and enjoyable, not an exam where everyone must achieve 100% correct on/for everything they do, otherwise they are a failure and should give up. Nothing in life is perfect. Learning while growing is endless. Making mistakes is inevitable. Does it really matter if you or I get 149 grams and not 159 grams?? Sorry for the digression, however, your plant will be fine, nothing to stress over, there is no great problem that will affect you harvest. Keep up your care and your plant will reward you with tasty flowers you will be proud of. Try not to get caught up in the "mine is bigger/better/more perfect type of power trip and enjoy yourself on this journey of discovery and learning. I have been discovering and learning for 35+ years and don't take anything too seriously any more. Middle of the road is just fine - learn the principles without competing and success will be the natural outcome. Growing is all about enjoyment, not ego tripping. And I still make mistakes and also learn something new, each and every time that I do grow! And I haven't weighed anything ever!! Hope this helps,............ Organoman.