Yellow Leaves Normal?

Hi mate, plant looks good so far. However, I think they are in need of a feed. A few of the lowermost leaves going a little yellow is normal if they are shaded, but it appears that some of the leaves higher up could be a bit greener. Get some general liquid fertiliser and apply as per the directions, but initially at half strength. Do this when you give them a watering. Feed and then wait a few days before adding to their water again. If they look happy, go to full strength and continue to feed them every so often. They are hungry plants when flowering, especially if you have intense light like you do.