I have these plants 24 inches under a “1500w” ...

It’s safe to turn on all your lights at this point. Do this: start at low power if you can and slide it up over the period of a few days. Slow subtle changes are always best. Nothing good happens quickly with plants, only bad stuff. Once at full power slide your lights lower 1” per day until you see signs of stress. It’ll be one of three things. 1. The leaves praying to the lights(upturned tips) 2. Leaf edges curling up 3. Top leaves yellowing. Once you see any sign of any of that back them up an inch. Now you’re in the sweet spot for this strain. Measure the distance and try to keep your lights in that range as the plants grow.