the same thing happened with my plants. my friend use to start them inside in february and flower them for a week inside and weed out all the males. this is completely normal and happened to all my plants last year, they had 7 leaflets when we put them outside and went to 5 then to 3 then to...
you should find heathmans setup which is also vertical. He was able to get over 700grams off a single 600 hps. There were about 80 plants i believe total