Distance 400w to a two week old...

bonuslazer

bonuslazer

Active Member
Sorry if this is a dumb question, but I just purchased a 400w metal halide light. I swapped out my little 23w CFL setup, but now I'm not sure how close my light should be. I read somewhere to start around 20 inches. Any knowledgeable info will be appreciated... thanks
 
jimbizzzale67123

jimbizzzale67123

Well-Known Member
Here is the best way to calculate, Move it as close to your plants as possible use ur own hand to fell the heat by placing it directly above the tops of the plants if it fells to hot for ur hand it is too hot for your plants. Depending on how powerful ur exhaust is and if ur light is air cooled I usually have my 400wHPS about 10in from the plants but that is just me u need to find out ur sweet spot. Just keep an eye on them when u lower it, and check them often.
 
Silky Shagsalot

Silky Shagsalot

Well-Known Member
two weeks is still a bit young, especially if you've had them under cfl's till now. you don't give any details, so i'd err on the side of caution. if you started at 20" and moved it closer by 2" or so every day for a week, you'd prob be o.k. then start the back of the hand method.
 
BloomBrothers

BloomBrothers

Active Member
If it's a seedling and not a clone, don't put it under any H.I.D period until the 4th node min..........Keep them under floros till then............
 
bonuslazer

bonuslazer

Active Member
jimbizzzale67123 said:
Here is the best way to calculate, Move it as close to your plants as possible use ur own hand to fell the heat by placing it directly above the tops of the plants if it fells to hot for ur hand it is too hot for your plants. Depending on how powerful ur exhaust is and if ur light is air cooled I usually have my 400wHPS about 10in from the plants but that is just me u need to find out ur sweet spot. Just keep an eye on them when u lower it, and check them often.
Click to expand...
I don't have exhaust yet but i do have a floor fan angled up at the plant and light... doesn't seem to hot in there. I adjusted to about 16" and it feels pretty cozy...
 
W

wiseguy316

Well-Known Member
use the cfls for a lil longer, you are wasting the light, it doesn't need that much right now,,think about a 400 for 1 lil plant, wait till it gets bigger. good luck
 
jimbizzzale67123

jimbizzzale67123

Well-Known Member
Looks good but u may want to go with what the guy above me said, thats a very small plant and u can have the CFL's right on top of it. I wold work on geting a exaust fan and closing that area up so when it is bigger u can concentrate the light on it. I would let it veg for a while so u get the most out of it.
 
bonuslazer

bonuslazer

Active Member
I think its doing good now... I'm gonna take your advice and try to close in the area with some mylar and pvc (so I can make a "shower curtain") I think I'm gonna leave the light under the 400 as it seems to be reponding well now that it has adjusted to the light.
 

Attachments

bonuslazer

bonuslazer

Active Member
jimbizzzale67123 said:
Remember to move ur light down U have some good node spacing now don't let it stretch too much.
Click to expand...
Yeah, I'm gradually putting books under the plant... its about 18.5 inches and around 85 degrees. Not sure how much closer I should put it. Some of the undergrowth is filling in as well, so I don't think a little stretch would be too bad. Thanks for light tips!
 
bonuslazer

bonuslazer

Active Member
jimbizzzale67123 said:
Remember to move ur light down U have some good node spacing now don't let it stretch too much.
Click to expand...
Stretching a little, and a little droopy... but I think overall things are fine. I'm wondering if I should add some supplemental light to the sides, but I don't want to overload the plant and stress her out... here's a few pics of the current growth

Oh and I cut off the bottom fans that were drooping so as to give more growing energy to the top sets...
 

Attachments

You must log in or register to reply here.
Top