Help please lowlife ak47 auto flowering

Hi all, i have 2 auto lowlife ak47s 5weeks into grow, 1 has been budding for about 2 weeks fine 60cm tall bushy in 5ltr container, grown in all mix and only feeding with liquid fish mix (3ml per liter of water) once a week and now it is budding i use (2ml per liter of water) top max, but leaves are a bit small and now they are starting to curl at the edges i have read up and think it may be Magnesium deficiency so i hope buy spraying them with epsom salts should solve the prob i hope. ok thats number 1, now the other is the same in a 5ltr container grown in all mix and only feeding with liquid fish mix (3ml per liter of water) once a week. Plant is nice bushy 60cm tall but only a couple of hairs near the top and when i say a couple i mean a couple, what is going on here?