quick lighting question

S

siense

Active Member

• Jul 15, 2008

• #1

I have 4-400watt dual spectrum bulbs what size area will this cover I currently also have been gifted 3-4'x2' trays.Any help is appreciated

 

blackcoupe01

Well-Known Member

• Jul 15, 2008

• #2

Id go with at least a 10x10 area, each light having its own 5x5 space to cover.

 

P@ssw0rd

New Member

• Jul 15, 2008

• #3

5x5 is asking alot of a 400, try 3x3 for 44.44 watts a sq foot. You could always go bigger but you will need to rotate the plants around alot to keep them uniform.

 

S

siense

Active Member

• Jul 15, 2008

• #4

so the 1600watts would be adequate for 4'x8'

 

T

T.H.Cammo

Well-Known Member

• Jul 16, 2008

• #5

siense said:

so the 1600watts would be adequate for 4'x8'

Click to expand...

Absolutely! The rule of thumb is "50watts of HID lights (MH or HPS) per square foot of growing space". So, 32 sq. ft. is dead on! Actually, you will be getting "better" coverage from 4, seperated, light sources than you would from a, theorhetical, single "1,6oo"watt light source because the light only has to travel about half as far, don't forget about "The Inverse Square Law".

The shape of the grow space is also important! A 6'x6' = 36 sq. ft. grow should give you much better results (at 44.4watts per sq. ft.) than a 4'x8' = 32 sq. ft. grow (at 50watts per sq. ft.). It's all about how far the photons have to travel through the air!