Lost but persistant

Hey guys second timer here,

The bigger plants i have are under 600w MH and about 6 ft away from the plants.... Temps avg between 70-80F/20-30 C--- Humidity is roughly 47Lo/67Hi
I did have a bug problem that i have been treating with neem and diatomaceous earth on the seedlings but the growth on them seems abnormal and they are under 32w T8 tube floros... I did get a ppm meter and read that i could have been over feeding which i can correct but i have no clue why they have the abnormal growth and color patterns.. they were doing fine a couple weeks ago... Growth on the biggest plant is at its best semi half ass.... I am wondering what the hell im doing wrong here.. Another thing is that the larger plants dont seem to drink all that much. they stay moist for quit awhile. All containers at 3g except the largest plant which is in 5gal..