Dying leaves and very small buds (hash plant end of week 7)

I had a very big and bushy plant ad week 6 with big leaves and a lot of tops, but the buds were only half the size they should have been, in beginning of week 7 the top of the plant started to get yellow and at the end of the week all of the big leaves had dropped and the rest of the leaves are yellow and rusty and the whole plant just looks like a bunch of stems with small buds =(

I have another hash plant a little bit taller with only 1 top and rest are branches, and it looks pretty healthy, the buds are a little bigger (not as big as they should be) and most of the hairs are white. they are both under their own 600w hps with new bulbs.

I'm Using
Atami hydro A+B
Atazyme
Ata xl
Bloomstimulator
Pk 13/14

I have been following all directions on the bottles the ph is allways 5.5-6.2

they started flowering with ec 1.5 when one of the plant started dying the ec was 2.6 and ph was 5.9

I moved the dying plant to a bubble bucket with ec 0.1 and ph 5.5 and just a very small doze of everything above)

Any other suggestions???

If your growing from seeds then the genetics might be shitty. ive heard of this happening with seeds that "looked good" but were bunk.