Light coverage

I’m using MH/HPS just unsure what wattage I need. 3x6 growing area and I’m doing SOG. I was thinking two 600 watt lights or two 400’s?? Help

Bud2theBone said:

I’m using MH/HPS just unsure what wattage I need. 3x6 growing area and I’m doing SOG. I was thinking two 600 watt lights or two 400’s?? Help

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general rule of thumb for hps is 50-60 watts per ft2. for flowering.....you can get away with half this for veg.



2 - 600s would be my choice for optimal coverage over 3x6...its a litte on the higher side at 66w per, but as long as you can manage the environment, 2 x 600s will fkn crush a 3x6 perfectly lol

I personally would go with 2 400s ( out of the options given )spaced properly for shared lighting.. which just might give you better control over the environment...Happy Grows!

God of Agriculture said:

I personally would go with 2 400s ( out of the options given )spaced properly for shared lighting.. which just might give you better control over the environment...Happy Grows!

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Ya its all about the heat for sure.


the 2 x 600s will offer much better coverage and overall penetration than the 400s tho, as long as the extra heat isnt a concern.


Now if hes not using the full 3x6 for canopy, he can def get away with the 2 x 400s for sure.

Regardless, both options will work, but i think the 600s will def provide bigger yields than the 400s.

diggs99 said:

Ya its all about the heat for sure.


the 2 x 600s will offer much better coverage and overall penetration than the 400s tho, as long as the extra heat isnt a concern.


Now if hes not using the full 3x6 for canopy, he can def get away with the 2 x 400s for sure.

Regardless, both options will work, but i think the 600s will def provide bigger yields than the 400s.

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Definitely..but I should clarify...I would use MH bulb with the 2 400s.. The blue wavelength has the deepest penetration before being absorbed by plants...but at the same time...I think veg time plays a big factor as well...BUT YES..if he goes with HPS he WILL NEED all the wattage he can possibly use without overheating..due to the fact that the wavelengths of it have such a shallow penetration.. Happy Grows!

2 x 500 watt CMH would be good. They are newer lights.

2 x 600 HPS would really rock that space but heat would be a concern.

2 x 400's would do the job but would cost a little in yields.

If the 400 watt HPS ballasts have an overdrive setting then use it and they would be ok.