When to switch to red?

i would wait untill i see white Pistils so like week 4 or 5

I would give her all the spectrum you got, just not too intense. I would try to be around 500 ppfd at the top, whether you dim or lower the light. She's looking nice.not sure if temps is an issue but best not to overdo the light but think you could push it a little harder. Maybe bring the light up a little as well and let the plant grow into the new spectrum/intensity. Make gradual changes and see how it affect the plant. I'm lazy and just put the light all the way up and run almost full power in my veg tent. my flower lights overpower my tent on 100 so I keep them around 60-75 percent and leave them at the top.