The bottom 1/3rd of half. You want any nodes that won't recieve direct sunlight removed. As you have plenty of room, allow them to grow for 2 more weeks. This is dependent on strain, if sativa or if breeder says it has a high level of stretch. Then you may need to flip now. It's strain dependent.
I run autos, but my sour stompers grew 4x their size when they hit flower. The breeder did list this though so I was aware.
I also listed and showed pics of my defoliation on my diary. Search my sour stomper diary and hopefully it will help you. I was terrified of removing half the leaves. But it helps more then it hurts I promise.
Goodluck
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