What's Wrong??!?!

my 2 plants are in the 4th wk of flowering and one plant is completely yellow with crispy leaves and the other one is following its footsteps.. my soil ph is 6.0 and i had half strength nutes...i already flushed them..what should i do?

sorry bout that..here they are..

"Magnesium deficiency starts in the lower leaves , the veins remain green while the rest of the leaf turns yellow, exhibiting chlorosis. the leaves eventually curl up, and then die. the edges of affeated leaves feel dry and crispy. as the deficiency continues it moves from lower leaves to the middle to upper half. eventually the growing shoots change from a plle green to white color. the deficiency is quite apparent in the upper leaves. at the same tim, the stems and petioles turn purple"

hope this helps

thanx i appreciate it

i flushed it and gave it some epsom salt dissolved in some water and still no signs of gettin better..