The feeder leaves main vein is brown and leaves are starting to drop off

Just put plant into bloom 1 week ago. The feeder leaves main vein is brown and leaves are starting to drop off. The feeder leaves are from the middle down being affected. I beleive this is this is a potassium deficiency? Sorry waiting for a camera to send pics.

brown or redish veins on your stalks is ment to be a sign of a good strain! cant tell you more than that without a pic or 2 some leaves will fall off naturally especially if your plant is well into budding! leaves will still grow at this stage try not to worry too much n give that plant a hair chop if you think it needs it!!!