How close to lights?

Kingrow1

Well-Known Member
When people ask how close a seedling or plant should be to a cfl/flourescent or any type of light the only answer that comes back is to put your hand there and if its not hot its fine.

This seems the most unscientific and most likely to fail method, would have thought total lumens would be your first consideration not what the back of your hand thinks.

This advice has always amazed me!
 

breakdancer0003

Well-Known Member
This seems the most unscientific and most likely to fail method, would have thought total lumens would be your first consideration not what the back of your hand thinks.

This advice has always amazed me!
It seems like that question is usually asked incorrectly / incompletely by inexperienced growers who would be lost in a full out explanation of light footprints lumen requirements ect.

Depending on there lights / ages of bulbs / air flow / ambient temperature / time in between when you can check / adjust the height ect. the "Ideal height" is at best a guess.

with all of that being said, heat is the easiest stresser to pinpoint and avoid so it makes sense to me to explain the ideal height in simple terms using a tool we all have and a sensation that is easy to describe.

I go with less is more when it comes to cultivating until you really have a feel for it then get more technical and try to maximize. Most people asking about " how far away should my lights be " aren't there yet.

I could be wrong though this could just be another cannabis rumor that spreads like wildfire but that's my view on the answer to the question.
 

jm 420

Member
thats not for cfl's put those as close as ya want
i dont see whats so amazing if it burns your hand gonna burn your plant ,this is for hid lites
de setups are a bit diffrent cuz of spectrum
 

kmog33

Well-Known Member
It seems like that question is usually asked incorrectly / incompletely by inexperienced growers who would be lost in a full out explanation of light footprints lumen requirements ect.

Depending on there lights / ages of bulbs / air flow / ambient temperature / time in between when you can check / adjust the height ect. the "Ideal height" is at best a guess.

with all of that being said, heat is the easiest stresser to pinpoint and avoid so it makes sense to me to explain the ideal height in simple terms using a tool we all have and a sensation that is easy to describe.

I go with less is more when it comes to cultivating until you really have a feel for it then get more technical and try to maximize. Most people asking about " how far away should my lights be " aren't there yet.

I could be wrong though this could just be another cannabis rumor that spreads like wildfire but that's my view on the answer to the question.
This is on point. So many new growers on here asking about adding co2 burners, crazy micros, all kinds of weird additions when really all you need is an 2 parter and calmag and a light and you can grow great bud. Adding little things after you have your setup/strain dialed in already makes a lot of sense. But if you add all of the crazy shit when you don't know what you're doing, all you do is cause problems for yourself. And because you have added all this wonky shit, you have a hard time even identifying where the problem originated.


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Kingrow1

Well-Known Member
This is on point. So many new growers on here asking about adding co2 burners, crazy micros, all kinds of weird additions when really all you need is an 2 parter and calmag and a light and you can grow great bud. Adding little things after you have your setup/strain dialed in already makes a lot of sense. But if you add all of the crazy shit when you don't know what you're doing, all you do is cause problems for yourself. And because you have added all this wonky shit, you have a hard time even identifying where the problem originated.


Sent from my iPhone using Tapatalk

Then you can appreciate that when someone asks how close to lights should my seedling be they are really asking a question on light, lumens etc and not about heat or what the back of your hand thinks.
 

Kingrow1

Well-Known Member
thats not for cfl's put those as close as ya want
i dont see whats so amazing if it burns your hand gonna burn your plant ,this is for hid lites
de setups are a bit diffrent cuz of spectrum
I grow plants and light is measured in lumens (with some allowance for par spectrum) sorry.
 

SPLFreak808

Well-Known Member
When people ask how close a seedling or plant should be to a cfl/flourescent or any type of light the only answer that comes back is to put your hand there and if its not hot its fine.

This seems the most unscientific and most likely to fail method, would have thought total lumens would be your first consideration not what the back of your hand thinks.

This advice has always amazed me!
I always thought this method is dumb as fuck. I live in a tropical state and work in the tropical sunlight every day for 7-9 hours. My hand only feels "comfortably warm" 5 inches away from 1kw hps bulbs but it will burn my plants at that distance.

Whats cold for me (70f) is warm for most people. Whats warm for me (85f) is uncomfortable to most people. I start my sprouts under 23 watt cfl's and keep them about 2" away for 7-10 days. If you use strictly cfl's (spirals or tubes)you can get them pretty close (2-6" depending on output and heat) to the plant all the way till harvest as long as your not exceeding 80-85f sometimes 90f depending on strain.

Then ill move them about 30" under 1000watt hps and move higher every week untill the leaves get nice and thick.
 

jm 420

Member
ok kirk lol
ill semd some photon misssles yor way


really your best response
use a lumen meter to check your lites output,or to take pics
educate urself before spreadingt intenet bullshit lol
ive won this fight more than once lol
 

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Kingrow1

Well-Known Member
ok kirk lol
ill semd some photon misssles yor way


really your best response
use a lumen meter to check your lites output,or to take pics
educate urself before spreadingt intenet bullshit lol
ive won this fight more than once lol
For sure you are right up to a point, technically we could just consider Par as two thin spikes on a spectrum graph at 400 and 700 to which youll get no argument back.

Truthfully and more to the point Par is a very complex subject, consider the experimemts which show that even the wrong kind of Par can grow a plant as quantity far out weighs quality when talking about photons. Even then most grow lights are attenuated more towards the photosynthetic portion of light and as such are not a far cry from the true amount of photosynthetic light available.

I dont see many wanting to move forwards with Par as Lumens is a reasonable consideration.

As youve cited Par i wonder just how much you use it in your daily grow (or is it just a talking point)? For sure Par is an easy subject but to accuratly measure and put into practice its a lot more technical mathmatically, unless you can afford a high range par meter.

Par involvels your daily light integral and gives you an average umol/s or average mol needed per stage of plant, light and distance. It sets when to begin your dark period and such in pro greenhouses.

Im happy to talk in terms of par since you like that, seedlings like 2-5mols a day veg at 6-10 mols a day.

Youmight find that lumens is a lot easier plus most lights are shifted towards the Par part of the spectrum where photons have more energy due to longer wavelengths so going futher can be a bit of a chore.
 

Kingrow1

Well-Known Member
It works , even if your super genius mind can't process the simplicity
What works? We all know Par works but to use it as a measurement is more tricky. Some bulbs do publish their mol readings such as Phillips but ive yet to hear anyone hear talk in mols/par here yet.
 
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