Hydroponics growing problem, grow is halted.

Hi guys this is my second time growing, first time I did in soil and it was great success but this time I bought Autopot. I put seeds in jiffy in May 14 and put them in Coco+Perlite in May 19. Its been roughly 20 days in coco but as you can see in pictures plants are too small compared to my first time in soil. After putting them in coco I give them water manually for 14 days and open the autopot watering system after that. First time I opened autopot didnt give them any nutrients and 2-3 day later I add FloraNova Grow in the reservoir. I followed the guide but I guess I made a mistake giving them nutrient late. Is this growing speed for hydroponics normal or am I overreacting? Please help this poor newbie out.