Great post, charts are another addition to any ones Bible of growing cannabis.

Thumbs up * infinity

So are we shooting for 100% PAR or is more beneficial?

O.K.; now for something completely different.

One could use these same formulas for calculating flourescents/compact flourescents??

..Just like with nutrients; too much is nothing more than waste. Too much light can actualy ADVERSELY effect your plants.

CaliGrower, What's up. Hey I sent you a pm awhile back, I guess I didn't send it right.

Great chart's, I didn't see anything about Light Mover's in any of you report's. I have been using track's for many year's. When I firts research them I was sold on the fact you could cut the sqaure footage in half,and use less watt's, Being that the light-mover's captured both sides of a room.

For example: If you have 12'x12' room,=144sq.and had 8000w.= 55.555w. per sq. And you had same sq.ft. but had four light-mover's and 4000w.=55.555, Being the factor that 12'x12' would be cut in half = 72sq.ft.

Covering the room with 4000w. instead of 8000w. is a big heat drop.

Do you have any chart's or fact's on this subject?. Later

The most common problem with LED lighting is during the flowering stage. The plant is looking for a different spectrum of light.

Detailed Information on Grow Lighting
http://www.pfolighting.com/Horticulture-Grow-Info.aspx
( also lighting chart )
Quote from article :
HPS (High Pressure Sodium) bulbs are the most efficient bulbs that are available for grow lights. They are high in the red and yellow parts of the light spectrum and low in the blue, this imitates the fall sun.

LED lighting also takes a special meter in order to read (lumes), this is a common mistake made with LED's

I have talked to the builders, they said they will have been working and will have a ( FULL GROWING SPECTRUM LED GROW LIGHT )

They said they will have them ready by the last part of the month.
You can look at their page.

http://www.ultraledlights.com

This LED Grow Light will have the same growing spectrum as the (HPS & MH)
I can't wait to see it , they seem to be the only ones looking closely at supplying the spectrums needed and keeping energy cost down.

I know not everyone is sold on LED.S yet, but I feel they have the best future

Helping Hand, Thank you for the chart's and site's. I will add them to my studies!!Later

Holy Sheep-Shit......I just learned a ton outta this thread....Thanks to all who contributed,great stuff.

This thread is primo. Bellisimo!! Thanks Caligrower.

Hi Cali, you have some great threads in this forum and all of them have been a huge help for me.

I had a question though. You always calculate the distance away from the bulb, but does it matter from which direction?

For example, let us assume that a plant is not under the reflector but still 14 inches away from the TIP of the bulb. Can your charts still be used in this type of situation or does your charts only calculate the 120 degree area under the reflector?