Finally legal in Germany - My first grow

Beginning of week 7 Hulkberry Day 49 I have defoliated some of the lower fan leaves that don't get much light anymore and had turned yellow or died off anyway. After upping the nitrogen dosage to fight a suspected deficiency, the tips of the upper leaves started to turn brown, possibly nutrient burn. Unfortunately that has gotten worse over the weekend. While the tips did not die off yet, they turned quite dark. And overall it's still looking a bit pale. But at least the buds develop nicely. Hope I can keep it somewhat healthy until harvest. Purple Queen Day 49 It seems to have finished stretching now. Buds continue to grow, but no trichomes yet. Although this plant received the same nutrient mix as the Hulkberry and is a week or so behind in development, this one show only a very slight nutrient burn. Day 50 @001100010010011110 @m0use Thanks for answering my question. There is so much more info I could provide but the question form is very limited. Guess I just worried too much, since the color change coincided with the tip burn. But I'm still a bit puzzled as to how this could be caused by temps. I have records of 3 different sensors (AC Infinity Controller with probe near the top of the plant, Govee Hygrometer and the Xiaomi Soil Sensor), that all show temps never went down that low. Usually around 72-74F at night. Only 1 night, 4 weeks ago where it went down to 70F. As far as genetics go I have not seen a grow on here where this strain changed color. I cold have accidentally mixed up the seed with Purple Queen growing in the other pot, but I was extra careful not to do that. Concerning Calmag, I didn't have any at the beginning. Considering my local tap water is high in both elements (according to the local water report, last published 02/2024) I didn't think it would be necessary. Guess it was still not enough or not in a form available to the plant. Next grow I will document EC better and ad Calmag from the start. Since I'm using organic fertilizers I try to feed with hardly any runoff. But the little bit I got was around the same EC as before it went in.