droopy leaves

here are some pics of two swiss sativas.
they have been flowering for 18 days under 575w of enviro.
Temp - 78-80 hum - 50/55
flushed them with water every second day for a week. Then fed them every second day with 700mls of ionic bloom (50mls per 10 ltr) and (40mls per 10 ltr)of big bud added.

problem- lower leaves going stripy yellow and stems very weak.pic 1

problem 2 - some leaves are curling down but are dark green, thees are at the top mostly around buds. pic 2

can someone please help with above.

looks like overwatering

First off bro you need to figure out what your soil is really wet or really dry I had the same problem 2 days ago and mine was cause I over watered and I let them sit till there was no water gave them very phd water and within 3 hours they began to perk if you need help PM me