My light at least!! Ok basically ive always believed the safe distances from your hps to your plant was from the very tops of your plants. Ive just recently saw this though http://i44.tinypic.com/2j0cyvn.gif which indicates that for my 400w bulb the 12 inch rule is actually only to the canopy but the buds are fine to be much closer to the bulb. Is this correct? So I've actually had my light about 4 inches too far away?
Have I just made a major discovery about light...
- Thread starter gubblebum
- Start date
well, the best way and the simplest way is to hold ur hand over the top of ur plant(s) and see how hot it is.
if ur hand burns, move the light, otherwise move it as close to ur hand as possible without burning.
thats all that needs to be done really. unless you have a cooltube or some other form of heat control which will mean u can move it closer.
if ur hand burns, move the light, otherwise move it as close to ur hand as possible without burning.
thats all that needs to be done really. unless you have a cooltube or some other form of heat control which will mean u can move it closer.
TeaTreeOil
Well-Known Member
HPS also emits heavy IR light(beyond 700nm). That's heat waves. These are some-what(around 20%) shielded by plastic/glass(cool tube), but can still fry a plant. Air flow doesn't alter them.
Observation is your friend. Experiment, but don't push it unless you're willing to possibly harm plants.
Observation is your friend. Experiment, but don't push it unless you're willing to possibly harm plants.
Little Tommy
Well-Known Member
Whenever I make a change in the height of my light I always monitor it closely for 48 hours. If the leaves are not showing signs of stress you should be okay. If you see the tell tale signs of heat stress ( little yellow stripes on the highest fan leaves) move the light away. After a while you will determine your perfect height. Once determined, I tie a string with a nut on the end (for weight) at the perfect height and adjudt my light so that the nut is touching the top of the highest fan leaf. I hope that helps.
tony maglone
Well-Known Member
I spent £ 5.50 on a light spreader and i can keep my 600 w hps 8-10 inches away no prob...simple cheap solution...
Greenisgold
Well-Known Member
Get a mover, and drop the lights.
JonnyDankness
Active Member
Movers are the way to go, I have my 600 watt maybe 7 inches away from the nearest top bud.
TeaTreeOil
Well-Known Member
A system which moves the light source around a room to cover many times the area using a fraction of the light/power.
SenorSanteria
Well-Known Member
Yeah, and even thats pushing it for me. I use two 150's. 3-4 inches from the colas.
moodster
Well-Known Member
where was your light spreader from for that ???
F
fureelz
Guest
1000w - 12/14" away im thinking of getting 2 600w instead...
dirt clean
Well-Known Member
hey get this, I measure my 400 conversion bulb yesterday and it was at 45k lumens according to the 15 dollar light meter and now today it is down to 30. Previously it always read 45. Weird.
dirt clean
Well-Known Member
oh yeah, i got my buds 1 inch away from my 40o becasue it was so cold and my vent was so good. I bleached all the upper portions of the buds. No hrat damage just light damage. You do not want that. I did not know that then. 
Ive got a 250 watt mh setup that is in a enclosed sorta metal box with a reflector and a glass sheet covering the bulb. how close to my plants will i be able to have my light baring in mind its got the glass between the plants and the bulb. would having a pc fan aimed at the glass help atall? Any help much appreciated.