Ich habe den Pflanzen ende letzter Woche 1,2g auf 1,2L Hybrid Dünger gegeben.

I think you are too close to the end of flower to be adding more. It shouldn’t matter to much at this stage if you do not add any more as I think you might have plenty of nutrients built up in the soil because I see some slight burning on the tips. Hope this helps.

If you are 2.5 weeks out from harvest I would not fertilize again... that is if its ready for harvest. If you feel the need to, then do half strength, looks like some burn on the tips. feeding its not going to doing much though this close to end of life. however It might have a bit more time in it then 2.5 weeks. hard to tell. Lots of white pistils yet. Also your plants where in flower at your week 3 in the diary. so you are on your 5th week in flower. Autos tend to bloom for 5-9 weeks depending on the strain.

I've used these powders. They are very potent. Also, you can't go by Grams per L. Depending if your water is hard etc. Also, you are PH'in these solutions right. Ph from these powders are in mid-low 6, for my water anyways. Start adding higher PK. But looks like it's ph related. You are flushing out that coco weekly to avoid salt build up.