What is the max wattage pre square foot?

[Newby]

Hello everyone,

"Assuming" a well controlled growing environment with near unlimited heat removal capabilities....what is the upper limit of lumens/lux per square foot?

Assume a CO2 conventration of 1500ppm and a ambient temp of 80-82 F

I understand that 1 1000W HPS is often used for a 4 x 4 area, has anyone tried 1500w or even 2000W per 4 x 4' area?

Also, what are your opinions on using only a HPS bulb for veg and flowering? I've heard arguments that either MH or HPS are better.

Thank you in advance for your responses.

 

[Boss]

The only max will be heat. You can use as much light as you want.

 

[Racefan]

I use a 1k HPS in a 3x5 area with a 4 foot light rail. My light is 4 to 6 inches above the plants. I am right at the verge of bleaching the leaves but not quite there. Bleaching is a form of heat stress and not the best idea. So in reality the answer is...as many lumens as you can supply and handle enviromentally without doing damage to the plants.

 

[Newby]

I have an idea that may allow us to use a bazillion watts of light without 90% of the heat. If you use a reflective light tube (like the skylight tubes), but at the end you use the proper rectangular or square shape to light your area, and if you use a 98% reflective mylar, you can keep the light much farther away and keep the same number of lumens per square foot. I would suggest you make your own custom shaped tubes or rectagles depending on individual need.

Example, if you have a 2' x 2' reflector and you hang a 2 x 2' tunnel of mylar from just under the light, down a length of 6', the # of lumens at the end of the 6' tunnel should be the same as the top, but minus only the 2% loss from the 98% reflective mylar. The secret is that the square footage at the bottom of the light tube is the same as the top. You can then tweak the shape of the bottom of the light tube/tunnel to perfectly match your space.

Now imagine that light above a sealed grow room shining through a thin glass so it is completely separate from the grow room. The light generates the same amount of heat, but now most of the heat (by far) will be above and not in the grow room. Now also imagine those lights being sealed and vented. While your at it imagine an amazing sexual experience...but I digress...

I understand usually the amount of light per square foot decreases rapidly as you travel away from the source because it is then lighting more and more square feet, at a 2x2reflector itself it is only lighting 4 square feet, and to illuminate a 4'x4' it is now diluted over 16 square feet.

Does this make sense? This theory of mine will be tested by simply using a lux meter just under the light, and then again at the end of the light tube several feet away from the light.

What do you guys think? Think it will work? Has anyone thought of this before, or am I the first to contribute the idea?

 

[Smokin Moose]

This is what can happen with too much light. You get bleaching of colour, and this can have a deleterious effect on your plants.

 

[Newby]

WOW!
Now is that from too much light or too much heat?

How many watts were you using and how far was the light from the bud?

 

[Smokin Moose]

That was from too much light. It was an experiment done by Urdedpal, one of our grow gurus. It was a cooled lamp placed very close to he plants to see what would happen. I am unsure of the exact details of height and lamp, but it goes to show that even more light can be an issue at times. Some call it overkill.

 

[Newby]

Hummmm,

I'm curious if the quality of the smoke was affected?

 

[Smokin Moose]

This is a cured bud from the plant I showed you earlier. Speaks for itself IMO

 

[Racefan]

I'd smoke it!!!!!!! Looks nice and frosty. Some say the bleaching and drying of the bleached area causes the plant to produce more trichs in a attempt to slow the drying and tp protect the area. It makes sense to me but I still think it would be better to grow and finish them in the best health possible.

 

[Newby]

Drooooooooooooooooooool,......