is 4500-5000 per sq. f too many lumens?

i have a box that is 4' x 2' x 4' = 8' sq = 32' cu.

i am using a MH / HPS 400W switchable light fixture- in a 6" cooltube hooked to 435cfm CF fan

the MH bulb is about : 36,000 Lumens

and the HPS is about: 41,000 Lumens

so...

the MH is about 4,500 lumens per sq. foot

and the HPS is about 5,125 lumens per sq. foot

CAN SOMEBODY PLEASE TELL ME IF THIS IS TOO MANY LUMENS OR IF 5-6 PLANTS CAN HANDLE THIS MANY PLEASE?? LEAVE ME DETAILS THANKS

i hear plants love between 7,000-10,000 lumens per square foot you have 8 square feet-----

I sure hope not. I have a 145,000 lumen HPS and a 45,000 lumen MH running in my 5x5 tent. Looking at about 7,600 lumens and 56 watts per sqft. From what I have researched, these arbitrary values are ideal for a non-CO2 grow.

In reality you should really be using the inverse square law to keep the lumen level at the plant above 5,000 to really keep photosynthesis kicking. The better the wavelength the more growth, but 5,000 lumens based the the inverse square law is fine in most situations. This is determined by the distance from the light source and the strength of the light.

Theres no such thing as too many lumens for an indoor grow.The sun un produces 50,000 lumens per sq ft in the summer time.

so what will cause my plants to bleach? i honestly thought it was from having too many lumens concentrated on the plants burning the chlorophyll

Usually this is caused by a deficiency.

You can allow a plant to get too close to a 1000w 145,000 lumen bulb and that can cause some damage, but most 400w and 600w bulbs can be used basically right on the plants.

The deficiency to watch out for is Magnesium. Most deficiencies are the result of an over-abundance of another element, over feeding, and usually a flush is required.

The sun is 10000 lumens per sq. ft.. Ideally you want to get as close to that as possible.

Snow Crash said:

Usually this is caused by a deficiency.

You can allow a plant to get too close to a 1000w 145,000 lumen bulb and that can cause some damage, but most 400w and 600w bulbs can be used basically right on the plants.

The deficiency to watch out for is Magnesium. Most deficiencies are the result of an over-abundance of another element, over feeding, and usually a flush is required.

Click to expand...

thats comforting, ill make sure to pay close attention to the feeding

62Blunts said:

i have a box that is 4' x 2' x 4' = 8' sq = 32' cu.

i am using a MH / HPS 400W switchable light fixture- in a 6" cooltube hooked to 435cfm CF fan

the MH bulb is about : 36,000 Lumens

and the HPS is about: 41,000 Lumens

so...

the MH is about 4,500 lumens per sq. foot

and the HPS is about 5,125 lumens per sq. foot

CAN SOMEBODY PLEASE TELL ME IF THIS IS TOO MANY LUMENS OR IF 5-6 PLANTS CAN HANDLE THIS MANY PLEASE?? LEAVE ME DETAILS THANKS

Click to expand...

Nope this is fine I have 10,000 Lumens PSF for 4 plants