I'm growing 50% coco mix and 50% Light mix. a...

Keep feeding a nute that has some nitrogen in it for another week or 2 until it stops doing its flowering stretch. That stretch uses a lot of nitrogen to fuel the rapid growth of the branches. You should also start feeding you bloom nutes in low dosage to start giving them what they need to be building buds. Once the stretch has stopped you can generally stop using the nitrogen nute as the bloom nutes usually have enough nitrogen to sustain the plant for flowering. You can also lookup the biobizz feeding chart and feed a little less than they say to start with and eventually go full strength.