I could be mistaking, but I think StinkyAttic is a 'she'. If I am incorrect, please scold me Stinky! I apologize, if so!

As for your plants, there's nothing wrong with switching to an 18/6 photoperiod...especially if your plants are only a few weeks old. The only time you do not want to interrupt the light/dark period is when the plant is flowering. But when you're vegetating, experimentation isn't going to hurt your plant. You might, in fact, find out just what your strain responds best to.

In early growth, some darkness actually helps the roots to become better established in the growing medium. When the lights are on 24 hours a day, the plant tries to focus too much on foliage production...which becomes very difficult (and possibly even stressful) for the plant due to the fact that the root system is still so immature. During the light periods, photosynthesis is causing your plant to absorb the CO2 in the air and turn it into energy. During the dark periods, the plant uses that energy to promote strong & healthy root growth. This process keeps repeating itself over and over again, and eventually you have a big & healthy plant to deal with. As for later on in vegetative growth, after the plant has a well-established root system...there is no wrong answer to this question. Some growers like to keep the lights on all the time, while others try to mimic nature, at least somewhat, by giving the plant slightly similar light/dark conditions it would receive if it were growing outdoors. I generally always keep my lights on a 18/6 schedule, and am never disappointed with my end result. Or, if I am disappointed, it's certainly not because of my lighting schedule...but rather because of me goofing something up with my excessive experimentation!

Hope that helps.:rastasmoke: