thank you both much for you help
by all the plants are 7 leaves with this problem, i have installation a automatic watering system with 26° water and this still go 2-3 week‘s because the plant‘s are small… and one time there get the biotaps tee 2 time till now.
maybe there have it by too much feed, i must buy a ph tester. a tds i have and this ist good ~1000-1200tds i think.
sunday i load mew pictures maybe we see more.