Not sure if this will help but I keep mine 91cm away before the sprout, then a few days after they go 60cm away from a 600 watt MH. Haven't had any issues, but to be sure hold your hand just above the seedlings. Can u leave your hand there comfortably? If yes you should be good you may even want to get the light closerAny one got any advice on the distance I should have my lamp from these seedlings? I was worried I had it to far away so have lowered it slightly.
Its a 250w MH. Its currently 75cm above and they were germinatet 9 days ago. Would appreciate any advice.
Cheers.
P.s. I realise why my last crop didn't establish a good root mass (I think). I had a temp of 28 to 30c at the beginning! I now have it stable at about 20 to 22c. Growth doesn't seem as fast as I remember, I think thats because the roots are growing more than above ground??
Cheers guys.
Will upload pics now.
Cheers pal! I had seen that chart... So my light is a little far away. I was a bit unsure about lowering it further as they are so young. I can lower it quite a bit and still keep the temps low 20 c.. Ov got an intake coming from outside and its cold out! Lol.
from my post here: https://www.rollitup.org/t/canopy-penetration.892500/#post-12139626
they will take all the light you give, but just beware of your temps,
leave a gauge down there to ensure you don't cook them,
good luck
how about some updated pix...?