We have 10 seedlings, about a week and a half old. I'm going to start running our 400w HPS hortilux. We've had them under 320w of Day and Soft White CFL's so far, and have run the lights 24 hrs. Should I switch to 18/6 right now, or give it 1-2 more weeks on 24??? (This isnt my first grow, but in the past I was never involved in the seedling stage)
you can switch to 18/6 anytime you want most people do it from the get go but I believe seedlings can use the little extra light in the beginning but as they get older I like to give them some darkness. I have noticed better growth with 18/6 than 24/0 to be honest so I see no reason to use 24/0 at all really but if you must only use it the first week or so of growth. You will be fine so change it over and lets those plants feel that extra light.
Thanks for the tip. Ya, i use 18/6 normally during veg but, like i said, have never done the seedlings before. I guess i'll get the HPS goin tonight and hook that timer up tomorrow. Thanks again
no prob and if the light is aircooled get that light as close as you can and for a 400 with good ventilation I would say around a foot from the tops is sufficient but if you can get closer by all means do it.