Here’s the thing. We don’t have a pic of how your plants look. If we saw how they look, we could give better advice. Here is how my plant looks and I topped every top on it. I topped to make the canopy even. If your plants are just growing and only have 1 main stem, just top that one main stem however far down you want. If you want more of a bushy plant, top it down about 2-3 inches above the top of the rest of the canopy. Hope this helps! Good luck.