I'm about to start my grow (already germinated seeds) I have a 600w MH for veg - I'm just wanting to know how far I shud hang my light above my new seedlings-??? And also should I leave the lights on 24 hours a day or 18 hours whats best and is there and benefit to having them on 24/7-??? Someone with experience on this ---- (would be really grateful) CHEERS !!!
Well I don't have alot of grow experience and also I have a HPS not a MH. Alot of what I read, MH burns your plant easier, I dunno why or how but I have red tons of post when someone had a HPS on a plant then switched to MH at same hight and burned the plant. I have seedlings under my HPS like 12" but I only have a 150watt, I would do further away if I were you. Maybe even put it under floros first to build it up a bit then put it under the MH I dunno, never used a MH before. Also, from what I have read, 24/7 is best for fastest growth. I read a while back about some kind of study, like 100 plants 50 under 24/7 and 50 under 18/6 and like 9 out of 10 plants under 24/7 were bigger at the end of vegging for the same amount of days. Some people like 18/6 for whatever reason... Some people like to let their plants sleep a few hours a night... I think trial and error... check it out, see what suits you...