Hi texastweeked,

Looks like u got nitrogen deficiency. using too much nutes in ur water can cause this as the soil tries to balance itself out. i got this from http://www.overgrow.com/edge/gallery...Deficiency.jpg - looks similar to the problem ur having

Plants suffering from this deficiency are distinct in their pattern of yellowing. Yellowing starts on the older leaves and progresses upward, leaving the top parts of the plant green.
Notice that the large fan leaves are yellowing and turning purple-ish. from the bottom up.

Feeding with a high N fert will clear it up, like an emulsion of fish at 5-1-1.

[Editorā??s note: Leaves will turn pale green, then yellow evenly. There are no intervenial striping or yellow patches. Color is uniform over the entire leaf. Yellowing is expected during flushing, as the plant is using up all available internal nutrients]