Yellow growth to be cut off?

hi friend it looks to appear to me you have a few things going on. with the yellowing leaves you have a deficiency going on, looks like you need just a bit more nitrogen and you may also want to add cal mag. when you feed the plants water real good until you have a small run off, then dry your pots out and water a bit more. you make sure not to cut off the new growth, the yellow lower leaves yes. for now though get the deficiency taken care off now as when they go in flower it is harder to control. if you have a all purpose fertilizer like 20-20-20 this would fix the yellow leaves and bring health back to the plants. i would feed this until flowering starts, then go to a flower booster like beastie bloomz. hope this helps