Welchen Dünger?

Whats good dawg. You may want to look at organic dry amendments mixes. While the nutrients in them are not usually immediately available to your plants, it will break down in soil overtime. You need to top dress your plants a few weeks before you think your plant will need nutrients. I suggest BuildaSoil's Craft Blend. Its got like 14 different ingredients in it tailor made for cannabis plants. You're going to want to topdress the plants with 1-2 tbsp per gallon of soil. I also recommend getting some organic compost but preferably worm castings. The compost/worm castings will provide a little bit of nutrients, but its main function is to inoculate the soil with the microbiology necessary to break down your dry amendments into nutrients your plant can easily uptake. Its a bit expensive, but worth as the hassle as sourcing multiple dry amendments for your plants is frustrating and takes a considerable amount of money and research. If you can't do BuildASoil Craft Blend, there's also Down to Earth, Gaia Green, Dr. Earth etc. Good luck friend! Hope you kill your grow.