rjfortune25
Well-Known Member
Just wondering how close is to close, to have a 400 watt hps bulb above you colas, without burning the hairs and shit!????
How close is to close!!!
- Thread starter rjfortune25
- Start date
drherbalist
Member
Stick your hand in between the light and the colas and see what feel right 
Raise or lower as deemed fit.
Raise or lower as deemed fit.
jane's phasm
Well-Known Member
Mine have touched the glass with no ill effects. I have a 250 CFM fan inline with the hood, so it depends on how good your ventilation is.
I have a 400w mh/hps setup. First time i set it up i had it about 10 inches above my plant and it fried em. Went out and bought a cooled hood and i can get within an inch or 2 and no issues, IMO picking up a cooled hood was one of the best purchases i made...no more worries about heat or light distance.
brewing up
Well-Known Member
around a meter or 2 should be fine
jane's phasm
Well-Known Member
Yep. it probably makes economical sense when you think about how much more growth you'll get by the gain in lumens from keeping the lamp closer.
PJ Diaz
Well-Known Member
troll alert!
GanjaGod420000
Well-Known Member
drherbalist said it right... If yer hand feels perdy cool at canopy level, u r probly aight... I keep my 400 watters about 16" up... But u should always take actual temp readings for your own setup, and not just set lights at whatever number someone throws out there... Plants like temps about like humans do... Right at 75 or so...
jane's phasm
Well-Known Member
This is where mine is set. I just swapped in the HPS and it's a couple of degrees cooler on average then the MH.
View attachment 2094138
View attachment 2094138
rollandtoke
Active Member
Pot calling a kettle black!
And @OP, put it no closer than you can have your hand resting without it burning.
PJ Diaz
Well-Known Member
I only troll trolls.
MacGuyver4.2.0
Well-Known Member
The folks posting in here telling you to use your hand are only giving you *partially* true advice. You do use your hand (or a real light meter if you can get one), but you use the BACK of your hand towards the lamp! The backside of your hand (yes the one opposite your palm) is more sensitive to heat than the front, or palm. The rule is: Start about 1 foot below the lamp with the back of your hand and hold it there for about 5-8 minutes. If you cannot hold the back of your hand there that long, than 1 foot is too close. Drop height by 6 " and test again. When you feel comfortable holding your hand there, so will your plant. 
209 Cali closet grower
Well-Known Member
I was able to get mine 8'' from bulb with non air cooled hood.
rjfortune25
Well-Known Member
okay thanks because i dont have a air cooled hood either... that will be my next investment next grow! just dont want to expierence light burn again which i have! My plants just stretched out but there flowering nice still and stalks are pretty fat at base so i dont really worry about wieght of buds. Heres a pic of were iam at!!!
PJ Diaz
Well-Known Member
Listen to this man. He knows what he's talking about.The folks posting in here telling you to use your hand are only giving you *partially* true advice. You do use your hand (or a real light meter if you can get one), but you use the BACK of your hand towards the lamp! The backside of your hand (yes the one opposite your palm) is more sensitive to heat than the front, or palm. The rule is: Start about 1 foot below the lamp with the back of your hand and hold it there for about 5-8 minutes. If you cannot hold the back of your hand there that long, than 1 foot is too close. Drop height by 6 " and test again. When you feel comfortable holding your hand there, so will your plant.
PJ Diaz
Well-Known Member
A small oscillating fan blowing between your light and canopy will make a big different with an uncooled hood situation. When I ran a 400 uncooled hood, I was able to get 8 to 12 inches away from the canopy without burning, but I had that fan blowing.
rjfortune25
Well-Known Member
yea i have a 6 inch inbetween them blowing straight up to light, not oscalating tho!
GanjaGod420000
Well-Known Member
420 TIme's absolutely right... But in my defense, I did say to get some actual temp readings via a thermometer... And as I always say, if u can keep your temp in chack, via fans, or whatever, you can put lights closer than if you dont have a fan keeping the canopy cool, and moving air...