Hi Beefy,

I do not see a problem with going to an 18/6 now for a couple more weeks-or not- depends on the size plants you want "in the end". When your plants are say "half the total size" you want them to be "in the end" you should go to a 12/12 because they will stretch and pretty much double in size during the flower process. Of course the type of plants, lighting so on and so on will vary, but, this has been my experience.

I recommend not doing trials with things that you are uncertain of. Stick to things that work. (18/6 - 12/12) After you get things down you can play all you want. Just my 2 cents.