Have I misunderstood the 35-50watts per square feet law?

kreikrei

kreikrei

Active Member
I am wondering whether I misunderstood the watts per square feet law.

Maybe it means x watts per square feet of canopy/plants NOT tent space? That would be more logical.

An extreme example to illustrate what I mean.
1 plant in a huge warehouse directly under a light should get the same amount of light intensity as 1 plant in small tent directly under the same light... no? (All other aspects being equal - such as light distance etc)

At least similar intensity - I guess reflective walls also play a role, which a huge warehouse wouldnt have, but a tent would have.

Thank you!
 
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twentyeight.threefive

twentyeight.threefive

Well-Known Member
kreikrei said:
I am wondering whether I misunderstood the watts per square feet law.

Maybe it means x watts per square feet of canopy/plants NOT tent space? That would be more logical.

An extreme example to illustrate what I mean.
1 plant in a huge warehouse directly under a light should get the same amount of light intensity as 1 plant in small tent directly under the same light... no?

At least similar intensity - I guess reflective walls also play a role, which a huge warehouse wouldnt have, but a tent would have.

Thank you!
Click to expand...
It’s per canopy space. There’d be no reason to figure out how to light up an area where nothing is growing.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
I'm more interested in having lights that hit a reasonable DLI and/or PPFD in flower (when your light schedule is 12/12) and not having to run your lights right up against your canopy. And also having that PPFD footprint be reasonably consistent to the corners/edges.

I'm currently running ~48w per square foot.
 
ProPheT 216

ProPheT 216

Well-Known Member
LeastExpectedGrower said:
I'm more interested in having lights that hit a reasonable DLI and/or PPFD in flower (when your light schedule is 12/12) and not having to run your lights right up against your canopy. And also having that PPFD footprint be reasonably consistent to the corners/edges.

I'm currently running ~48w per square foot.
Click to expand...
I notice I get really nice buds at about 36 inches under the light, more towards the middle of the tent and by tent walls because of reflection. These buds at 36 inches under light are compairable to those that grew a foot higher, both in thickness and overall quality and weight. The plants seem to like a wide range of distance, 18 to 36 inches on my Spider Farmer leds. A wide range of great light production.
 
kreikrei

kreikrei

Active Member
ProPheT 216 said:
I notice I get really nice buds at about 36 inches under the light, more towards the middle of the tent and by tent walls because of reflection. These buds at 36 inches under light are compairable to those that grew a foot higher, both in thickness and overall quality and weight. The plants seem to like a wide range of distance, 18 to 36 inches on my Spider Farmer leds. A wide range of great light production.
Click to expand...
I am trying to visualize this.
Would it looke like a hockey field ( but square) and the plants would stand where usualy the goalie stands? In other words, in the middle but near one of the walls?

Then - wouldnt it be even better if the plants were in the corners? then light would reflect from 2 sides like a letter "L". Though - 1 side would get much more reflection then the other.
 
LeastExpectedGrower

LeastExpectedGrower

Well-Known Member
ProPheT 216 said:
I notice I get really nice buds at about 36 inches under the light, more towards the middle of the tent and by tent walls because of reflection. These buds at 36 inches under light are compairable to those that grew a foot higher, both in thickness and overall quality and weight. The plants seem to like a wide range of distance, 18 to 36 inches on my Spider Farmer leds. A wide range of great light production.
Click to expand...
I don't measure my light distances. I use a quantum light meter to measure PPFD a few inches below the tops of the colas and check throughout my tent I also do that with my tent as zipped up as possible so that I get greater accuracy with the reflections. Because my space is rectangular, I have three lights across its width and can adjust all three to make sure they're appropriate for the plants (or colas) that are underneath each light. This also allows me to start the plants under a single light then as they get bigger I space them out and turn on lights to make sure they're covered.
 
ProPheT 216

ProPheT 216

Well-Known Member
kreikrei said:
I am trying to visualize this.
Would it looke like a hockey field ( but square) and the plants would stand where usualy the goalie stands? In other words, in the middle but near one of the walls?

Then - wouldnt it be even better if the plants were in the corners? then light would reflect from 2 sides like a letter "L". Though - 1 side would get much more reflection then the other.
Click to expand...
Yes, I take my clones from flower to encourage crazy growth, then control and support the plants with 2 nets. I add a plant every 2 weeks and take one out every time I add. I manage to fit 5 into a 5x5. But pots placed like this

| p p |
| p. |
| p p |

Just adding my fifth where ever it seems best
 
calvin.m16

calvin.m16

Well-Known Member
I've vegged plants under 720 watt LEDs dimmed to 180 watts, even 2 feet away from the plants they grow beautiful. You gotta test it and see. Different spectrums, light sources, etc..
 
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