HELP! browning yellow leaves

[clyde]

I started 7 clones in pots outside. It is now week seven and all are growing well & starting to flower. However the bottom leaves on one plant have been turning yellow & browning. Thought it might be a phosphate deficiency so added some bonemeal. However leaves continue to yellow & brown. None of other plants have this problem yet all planted in same medium , same sun and same watering? Any sugestions?

[oldjarhead100]

from the pictures I would say and I could be wrong you have root issues ,turn the pot over and let the root ball drop out of the pot the roots should be white or just flush with water until you have runoff and check the PH,PPM of the the runoff water