Seedlings - 18/6 or 24/0 ?

I just popped 8 Bodhi Dream Lotus; in day 2 now. I have a 400w MH 18" from the top of my seedling greenhouse at 18/6, and they are stretching a little bit during the dark period (about 1.5" tall now).

I don't want to run my 400w 24/0 because I still have a little work to do on ventilation/temps. I'm wondering if it's worth spending the time and money to get a few 24w 6500k CFLs 24/0 for a week... or just run my 400w 18/6. In outdoors there is a dark period, so it should be fine, right?

I've vegged with T-8's before at 24hr's and the plants loved it but I ran them the first 3 weeks that way. I don't run my MH at 24 hours just do to heat and cost issues. If I could run my MH at 24 I probably would still stick to 18/6. Just from my observation the MH at 18/6 did better than the floru's I had at 24/0.

Yes you will be fine and good Luck!

One guy did a lot of research on light cycles. He found that 20/4 and 24/0 were both
better than 18/6. He decided the 20/4 cycle the best because it does save the bulb a few hours a day.

BigSteve.

I like 20/4

In my experience I have found that 24/0 produces veg plants with tighter internodal spacing, if there was any difference in harvest amounts it is by grams so it is all relative... I think the tighter node spacing is due to them not having a "stretch period" either at night or when the lights first come on.

Thanks for the input, I think I'll try 24/0 this time with my MH.