Need some help...i have about 20 seedlings in starter cubed in party cups under about 275 watts of cfl's...they are 6 days old ....my question is how old ,big ,tall do they have to be before i can put them under a 600 watt eye hortilux super hps bulb with digital ballast ...?? the reflector is air cooled ...??
in my experience you can put them under hid anytime as long as you start out with the light way higher then needed and gradually bring it down. if your concerned at all, wait until they have 3 or 4 nodes.
....had the 600 waat hps light about 15 inches or so from the seedlings...will they be ok ....they had been under 300 watts of CFL for 5-6 daysthey still look healty but there was some stretch from the CFL's and i was trying to compensate .... ...they are now about 20-30 inches away
did they suffer any burns or shriveling? if not your fine. the distance you have now is good to start. bring it down a couple a day until you get it where it needs to be. for a 600w, 15-20 should be good depending on ventilation.