When is it time to change to bloom nutes?

My outside babies are all showing hair on their cootchies, as they should now going into pre-flower. Actually, this little Lemon skunk is just covered in hair, growing from the very bottom of the branches to the top. It's been pretty warm here, and the calyix's are longer than they normally would be, showing a bit of heat stress. Overall though, all the plants are very healthy and doing good going into the pre-flower/flower stage.
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I've used DG Foliage pro and Protect during veg, and will be using DG Bloom before long.
Questions being- (1) At what point do I switch over to the Bloom? Is it done gradually? Should I use the 2 together during the transition, at what strenth?
(2) Is this little Lemon Skunk going into early flower? She is very nute sensitive, and I'm afraid to hit her with much of anything until I can gather more info, here.
Choke, cough, cough, wheeze.
Bong hit
Wake and Bake!

Thanks! That's pretty much how I figured it should work. My veg growth appears to be slowing slightly, with most of the new growth filling out the inner/lower nodes. They're really filling in nicely.
Here's my Northern Lights- I've had her tied down from day 1. The main trunk is approx 4' long, and the branches tied out left and right span nearly 8'. All tied down about 6" off the ground.
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