My last few runs I started running sensi veg nutes for first 10 days sometime 2 weeks into flower. I use my bloom boosters but I read somewhere when you flip its still in a veg stage so I just kind have rolled with that and it really helped from what I was doing before. I suppose starting bloom nutes a week before flipping would be same concept..Another thing,when I first started using sesni A&B I only feed once a week..I would feed,water,feed,water etc... Then after a few runs of decent grows I switched to feed,feed,water all through flower with sensi and it was a huge difference. Food for thought..Also dont be bashful...In flower your plants need less N and more P K...But i have found it helps to mix up your bloom base nutes and then add about 10-15% of grow A for a little N. Made a huge difference in my garden. you can Cut out the added the Grow A in the last 2 weeks before harvest. Just keeps them healthy and not rushing to that yellow as you go through flowering. But these are what works on my plants..trial and error will let ya know. But these tips helped me a ton