100+ watt per Square Foot ???

[dank.frank]

Is there anyone here running at or over 100w per sq. ft.? If so, does it really and truly increase the density/weight of the final product?

It is my understanding, that when running this high of a wattage, the plant will use more nutrients and need more than adequate ventilation for fresh air / Co2 for this to be of any benefit.

What does the general populace think?


dank.Frank

 

[Phillthy]

i believe environment is all about balance. too much of any one thing would not be beneficial if the entire equation is then thrown off. my two cents...

 

[magiccannabus]

It's more important to think cubic footage in my opinion. Cannabis only needs so much light, but since most people light their plants from the top down, from one light source, there's lots of light at the top, and not so much at the bottom. So to make up for the lack at the bottom, a larger light is used, which grossly over-lights the tops to satisfy the depth requirements of the whole grow.

While I would never recommend anyone buy one, the Phototron did represent a great new concept way back when it was introduced. It's a shame the idea never got developed properly, or sold for a reasonable price. Basically instead of trying to pour light through the canopy by saturating the tops, they hit it with light from all sides. So now your light would be more even, and you'd only need to use a sufficient amount of light to reach the buds right next to the tubes and a bit beyond.

So basically that's my thinking with my current grow. There's absolutely no good reason to over-light cannabis plants. There's only a certain amount of photosynthesis that can happen at a time in a certain cubic foot of plant. My plants sit so close to light sources, and the light is so uniform that I won't need to pass that saturation point anywhere. That's why I think T8 tubes are sufficient for the job.

So, if you look at my grow space on a floor space perspective, it's 250W per square foot. But since I am growing with vertical tubes, one must look at the light saturation by volume to understand how it will really grow. My cabinet has about 8 cubic feet of growing space, lit by 512W of tubes, or 64W per CUBIC foot.

A top down 512W lighting system would cover about 10 square feet at 50w per square foot, but If the light is 24" off the top of the pot, that means you're lighting 20 cubic feet, or only getting 25.6W per cubic foot.

I mean think about it, you're trying to light plants, not the floor....

 

[dank.frank]

well, that is the purpose of an air-cooled hood and raising/lowering your lights. The question is not really about efficiency...I have tried using multiple 4 foot fluros in a small space, mixed spectrum, all around the plants....didn't care for the results in all honesty. That is when I switched to HPS...have been much happier. However, I am working on a re-design, and was questioning if it is necessary to have 100w per sq ft. and if there is any true benefit to it say over 60-75w per sq. ft.

I do understand what you are saying...and yes, light does diminish very quickly in a vertical perspective....but still, lowering/raising the lights really does, fix this situation, at least in my situation...

 

[SevenSeeds]

wow magic nice post that was a great read!

 

[minttu]

It's more important to think cubic footage in my opinion. Cannabis only needs so much light, but since most people light their plants from the top down, from one light source, there's lots of light at the top, and not so much at the bottom. So to make up for the lack at the bottom, a larger light is used, which grossly over-lights the tops to satisfy the depth requirements of the whole grow.

Couldn't agree more!

Light dimishes to 1/4th as the distance doubles so it really isn't solely about the surface area, but more of spreading light evenly across the plant. Providing every branch optimum lightning conditions.

I have a plant under 250W + 104W of CFL and as the plant's top is VERY wide, it actually blocks a heck of lot light! CFL lights for the lower branches will hopefully make a difference in the end, and they are balancing the spectrum too. And a 250 watt won't penetrate too much foliage.

I'm now at 120W per sqft, or mere 27W per cubic foot.

I don't know if it works the same in outdoors as there is lots and lots of light and it probably will penetrate more foliage, and therefore "watts per sqft." works better in the sun light?