plant problems

please help not sure what problem or how to fix maybe root bound maybe nitrogen defecency but leaves are yellow and falling of in week 4 of flowering stage can anybody help

This is normal during flowering, what are you feeding it?

pale green and completely yellow leaves is not normal at week four, maybe at week 8

but I agree we need more info, like what your feed em and if you made a repot before they began to flower or if they are in "used" up soil and your not feeding em anything ?

up your nutrients dose a bit, both regular (NPK) and the micros like Ca and Mg (think I saw some brown spots in there as well but could be mistaking with them pictures)
the pale green color is a sign of N deficiency (so is the yellow as the plant use up stored N in the lower fan leaves) but remember your in week 4 of flowering, normally you want nice dark green plants at this stages and then let the N level drop a bit, so dont over do it, at this stages its actually more P and K you need in larger amounts

I agree with Slip. Not normal at 4 weeks. Take a PH reading before making any changes to make sure you don't have a lock out of nutes. If the PH is in range, consider adding more nitrogen to the feed schedule. If you are using Bloom food, supplement it with Grow nutes (nitrogen heavy).

Feed with some CalMag +

I tend to go along with Nitrogen dificiency, your plants looks pale.