Insomniac

I am a novice at this and am asking for advice.
4 Norther-Lights - Very thick stems, dense foliage, short vertical distance between nodes
The stems are brittle not flexible so I have stopped trying to bend the stems by force.
I have topped or cut off the new growth on each plant two times to force side shoots.
I have placed an iron barbecue grill grate on the top of three plants and am letting gravity (the weight of the grate), convince the plants to spread out and stay short during the vegg cycle.
The plants are about 7 weeks old and 6 inches tall, and so dense that it is hard to even see the stems. They are under a 400w HPS 24 hours a day and look very strong.
The 4th plant is only 3 weeks old and has three nodes. All 4 plants have been transplanted into large pots.

None of the plants have started forming staggered stems yet, they are all still growing two at a time, that is, two branches at each node, so I assume that I can't switch the lighting to 12 hours on and 12 off yet??

Does this sound like a worthwhile experiment? Any ideas? I ask because all 4 plants are in a 2 foot by 4 foot closet with only 5 feet as the highest that I can raise the light.

Thanks in advance for any suggestions

CRAZYTRAIN

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