First Grow, Organic, 80x80

Sadly i had some problems this week and didn't took much pictures, sorry for that. On Monday i wanted to start flowering but i noticed some discoloration on the bigger Plants in the back. The plants in front were just fine, nothing at all on them. So i waited with flowering. The top leaves on both plants were completely yellow with dark green veins in the middle. RG #1 in the left back not so much as RG #2 in the right back. Lower leaves were fine. On my pictures it's already much much better, sadly i didn't do any when the problem did occur, so you can't see how bad it was before. :( After some searching it seemed like its a zinc deficiency, most likely caused by a nutrition lockdown. Since i use Biotabs it can't be the Ph value, since it's getting regulated automatically. Still i checked the Ph value and it was between 6 and 7 so it should be fine. So for my understanding it had to be either overwatering or too much nutritions which got flushed out of the biotabs while watering them. I really tried to always wait until the pots are very light and almost completely dry before watering them again, like 2.5l on 11l pots, the right amount until i get a few drops water out of the pots on the bottom, every 3-4 days when they showed signs of needing water. From now on i will do the same, but with 500ml less water and no drain and hope it will be fine. If you got any tips please let me know, since im still a noob. RG #1 looked like nothing ever happened after 2 days, but RG #2 still shows signs of it until today. The darker green color is coming back, but slowly. Sadly i didn't took pictures on the first days, so i can only show how it looks right now on RG #2 and even tho you can still see it, it's far better then before with complete yellow leaves and just dark green veins. It still does not look ok, but the darker green is coming back for sure step by step. RG #1 is getting completely out of hand, even with scrogging, i will have to start flowering tomorrow or i really get height problems. So i turned all fans up now, light will go to 12/12 tomorrow and also from 75% to 100% power. See you next week in flowering and please pray for me that they won't get too high and no more problems occur, i can smell the hermies already :D Also thanks for keep pushing and helping me, i really like that site more and more. I look forward to keep this updated every week, it's really fun.