Light distance and lumens per SF for SOG

blueX

Active Member
Im going to grow SOG style and i have few questions:
1. For 600w HPS, what should be the distance between the lamp and the top of the canopy ? From what iv'e read it should be around 1.5 feet. Should i increase it to 2f because im going for SOG or it shouldnt be different ?

2. What should be the light intensity(lumens per SF) in SOG (flowering) ? I know it should be around 7k per SF and could go up to 10K(or even more - but that's not really practical). Should it be different in SOG ? - Iv'e read that it can and should be.

3. If ill use cool tube, how close can i get the lamp (again, SOG) ? Also i want to know if i can use 1 blower/extractor for few tubes or do i need one for each ?

thx :)
 

capncash

Well-Known Member
as close as you can without burning the plants. that is the general rule. there is now way to tell you an exact distance.
 

blueX

Active Member
as close as you can without burning the plants. that is the general rule. there is now way to tell you an exact distance.
I know that there is no way to know exact things but im looking for avg's and general info because i want to do the math in order to plan things right.
 

capncash

Well-Known Member
18in is about right. why would you want it higher doing scrog? where are your fans? what is the temp of your room? what kind of bulb is it? what kind of hood? is the hood enclosed with glass? are the hoods cooled with air? water? how big is your room? how many lights do you have going? there are a lot of variables. thats why you cant say 18 inches every time.
 

blueX

Active Member
18in is about right. why would you want it higher doing scrog? where are your fans? what is the temp of your room? what kind of bulb is it? what kind of hood? is the hood enclosed with glass? are the hoods cooled with air? water? how big is your room? how many lights do you have going? there are a lot of variables. thats why you cant say 18 inches every time.
Nothing is done yet, im on planing stage and everything is open for suggestion. Im trying to get optimal conditions - but stay reasonable.
No variable is strict.
 

blueX

Active Member
Check these........
I already saw those charts but thx .
I guess my question is if SOG method require diferent environment from regular grow ? Cause the plant go to flowering a lot earlyer therefore i guess the plant is weaker.
 

nickfury510

Well-Known Member
I already saw those charts but thx .
I guess my question is if SOG method require diferent environment from regular grow ? Cause the plant go to flowering a lot earlyer therefore i guess the plant is weaker.
no.....the difference between sog and a regular grow is that sog is pact in tighter to take advantage of the total light canopy and make the most out of your space. with a standard grow where the plant is let to grow natural with less plants per foot you will get holes and voids in your canopy. as far as light space. a 600w will light a 5x5 area good, and a 4x4 area great. because you are growing sog and will focus on the top canopy you can let the light spread a little more due to the fact you dont need the penetration to get to the under bud because there is none in a sog...hope this makes sense:leaf:
 

blueX

Active Member
I still cant get things right(mathematically).
If i put the lamp 1.5f above the canopy, according to the inverse square law a 600w HSP(~90K lumens) will make 40K FC(90000/1.5*1.5).
If i want to have 7K lumens per SF it means that i need 600w HSP on every ~5.7 SF area(40000/7000).
Its a lot more then the recommendations here and more then what i see on the journals...
What did i calculate wrong ?
 

blueX

Active Member
no.....the difference between sog and a regular grow is that sog is pact in tighter to take advantage of the total light canopy and make the most out of your space. with a standard grow where the plant is let to grow natural with less plants per foot you will get holes and voids in your canopy. as far as light space. a 600w will light a 5x5 area good, and a 4x4 area great. because you are growing sog and will focus on the top canopy you can let the light spread a little more due to the fact you dont need the penetration to get to the under bud because there is none in a sog...hope this makes sense:leaf:
It is.
I still want to be able to do the math right and i cant figure out what do i calculate wrong - if you can help me with that it will be greate(1 reply above).
thx.
 

capncash

Well-Known Member
dude this is an art more than a science. you can do all the math you want its not gonna make a successful grow
 

Maxbeasily

Active Member
it may be a bit late but, your math is right. however, the lumen for light bulbs are rated at 1 foot distance. so essentially 90+Lumen will be emitted if your closer than 1 foot.

i have a 600W HPS Digital, using a 6'' cool tube and a 5"s&p fan. the results are amazing you can touch the underbelly of the cool tube, so no worries about buring the colas.
 

HigherLearning420

Well-Known Member
this is way late...but i just cant help but comment on how difficult your making this. dont try and grow weed like a mad scientist. use trial and error, throw that light in there with a fan and see how close you can get it. your worrying wayyy too much
 
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