I am just growing the same and I am a week ahead of you.
You can definitely defoliate. I started it at around week 6/7 and did it rather drastically now which they seem to love.
They drink quite a lot for the size they are.
Mine are also taking slightly longer than expected. Just give them time.
I have them on a19/5 lighting schedule since the beginning. They do the rest by themselves.
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