If you use that method's principles and apply it to the photoperiod manipulation that's in the Grow FAQ, How do I manipulate the photoperiod for larger yields?, then you'd be one crazy weed growin sucka.

I'm too tired to figure it out on my own right now to see if the numbers would work for modifying that photoperiod scheme into the 18hr cycle... If it can be done, then I hope someone tries it. If not, just try the 18hr cycle by itself.