Newbie with a lumen question

[TitanEntity]

Hi to everybody, another question from a Newby, I would like to know if having 20,000 Lumens in a 6.2 square foot grow box is over kill for 1 sativa plant?

That works out to 3100 lumens per square foot. Am i capping out the plants ability to absorb anymore light?

I know that the extra light wont harm the plant because it's been fine so far. My question am i wasting my electricity?

180watts of 6500k
160watts of 2700k

 

[TitanEntity]

Bump

 

[B1989]

I'm not overly scientific but i'd say as long as the heat in the cab is manageable you're all good. Maybe someone with more knowledge of lumens/sq.ft will chime in..
Looking good by the way

 

[Scientific]

I'm not overly scientific

I am overly scientific.

You can buy a lux meter at Amazon for about $15. That would answer your questions with actual data. I would really recommend that.

Go for about 50,000 lux or so at the surface of the plant--roughly the same brightness as a sunny day.

Just to do a little back-of-the-envelope noodling:

6.2 square feet * 6 = 37.2 square feet for the surface of a cubical grow box.
37.2 square feet is 3.5 square meters.
One lux is one lumen per square meter.
20,000 lumens spread evenly over the interior of your grow box gives 5,700 lux average illumination over its surface.
As you know, CFLs work best when they are a couple of inches away from the plant, and that will give you a *much* higher lux value--right up there at the 50-60,000 lumen range that you want, in my experience.

None of this is taking into account PAR values, overstated brightness values from manufacturers, and lots of other confounding complexities.

My guess is that you should be in very good shape with the setup you've got all the way through flowering assuming that your plant doesn't get a lot bigger. I have a plant that's doing very well with fewer CFLs than you have, but they are closer and in a more confined area.

Four CFLs, five LED light bulbs, and one LED grow light for roughly 11,000 lumens, but all bulbs are within inches of a Dwarf Low Flyer that has been trained into a hemisphere with about a 15" radius.

As B1989 said, you're looking good.

 

[TitanEntity]

I am overly scientific.

You can buy a lux meter at Amazon for about $15. That would answer your questions with actual data. I would really recommend that.

Go for about 50,000 lux or so at the surface of the plant--roughly the same brightness as a sunny day.

Just to do a little back-of-the-envelope noodling:

6.2 square feet * 6 = 37.2 square feet for the surface of a cubical grow box.
37.2 square feet is 3.5 square meters.
One lux is one lumen per square meter.
20,000 lumens spread evenly over the interior of your grow box gives 5,700 lux average illumination over its surface.
As you know, CFLs work best when they are a couple of inches away from the plant, and that will give you a *much* higher lux value--right up there at the 50-60,000 lumen range that you want, in my experience.

None of this is taking into account PAR values, overstated brightness values from manufacturers, and lots of other confounding complexities.

My guess is that you should be in very good shape with the setup you've got all the way through flowering assuming that your plant doesn't get a lot bigger. I have a plant that's doing very well with fewer CFLs than you have, but they are closer and in a more confined area.

Four CFLs, five LED light bulbs, and one LED grow light for roughly 11,000 lumens, but all bulbs are within inches of a Dwarf Low Flyer that has been trained into a hemisphere with about a 15" radius.

As B1989 said, you're looking good.

Thank you for the information kind sir, your plant looks impressive .