There has been long debate on this issue and I personally think 18/6 is better then 24/0. The obvious reason, a savings in $$ on your electric bill. The other reason is after watching MJ grow indoors in my controlled environment for a very long time, you can observe very subtle but obvious behaviors of the plant. Roughly 2 hours before lights out, my plants start to droop in anticipation for the dark period. Roughly 2 hours before lights on, they perk back up in anticipation for the light period. The reason this happens, since the plant is not Photosynthesizing, it is taking all stored energy (sugars) from the day and moving them to the stem and down to the roots. Though roots grow 24/7, they do a majority of their growing in the dark. From my OWN experience, if you want a strong healthy plant with a strong rootball, a dark period is key. Of course, in 5 minutes somebody here will come along and totally disagree and give their own take. Here is a picture I took of a plant that was only in a 3 gallon container from a 16oz solo cup for SEVEN days. You tell me if this is healthy accelerated root growth or not? :thumbsup:

GTD