If you prune for single cola leave the bottom leaves on the bottom branches on as kind of like booster packs. Take off the buds when they first start to develop on the lower shaded braches. A plant starts turning at the top progressing to the bottom on the first and second turning (and the third but not worth the wait) The idea is not only will the energy be focused on the main single cola but flowering time is shortened as you dont have to wait for the little crap nugs to turn. This is why tall plants usually take a longer time to flower.

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