Yellow Leaves

Whats wrong? Some of my plants that were transplanted a couple of weeks ago are developing some of the lower more mature leaves yellowish. What could the problem? thanks for any help.

that depends on how fare along you are... if you are in the final flowering phases then lower, mature, big leaves will begin to discolor and die off, perfectly normal..

but if youre not that far into flowering or even in still veg, then weve got a different story...

where are you at in your cycles?

I am not sure about the age of the plants because I bought them a few weeks ago as clones. I am attempting to put them into the flowering stage right now turing the lighting from 18-6 to 15-9 and eventually the day after tomorrow 12-12. Thanks for any help!

pics?

if they have been in the soil for 4 weeks they could be running low on nutes, do you feed them?

how big are the containers?

any other info?