How Much light?

[Mikey09]

I am planning a new grow room. It is going to be in my bbasement, I am building a room that is 2.75' wide, 7' tall, and 6.3' long. I want to buy a HPS ballast and such, but I need to know what size I will need for the room. Will 600watt HPS be sufficient?

 

[bombbudpuffa]

Yes, a 600w should work.

 

[Mikey09]

I was hoping. i calculated it out, and if i wanted 2500 lumens psf i would have to put out 300,000 lumens... A 600w hps only offers about 90000.. Im not quite sure how it all works anyways.

 

[pcduck]

3000 lumens/sqft your plant lives but does not thrive

5000 lumens/sqft your plant thrives, this is what most indoor growers strive for 5000+ lumens/sqft

The sun 10,000 lumens/sqft

 

[Mikey09]

So I am going to need about 3 1000w Hps lights to get a good yeild from the plants?

 

[pcduck]

You figure your light usage by square feet and that is done by multiplying length x width in your case 2.75' x 6.3' = 17.32 sqft

 

[smokeytimes]

I would think that two 400HPS/MH would be best since this room is so much more rectangle the spread of the light over the canopy would be much better than having just one source for that light. This is why I choose to build my room as sqaured as I could I have a 600watt in my 3.75' x3.75' room that from what I figure I am getting about 6,423 lumens/sqft

 

[The Hemp Goddess]

Your math is incorrect somewhere. You have 17.325 sq ft (2.75' x 6.3'). You need approx 86,625 lumens for that space. A 600W HPS puts out about 90,000 lumens. However.....with a space that long and narrow, the ends of the space will not be getting enough light. You will probably want to rotate your plants.

 

[pcduck]

Your math is incorrect somewhere. You have 17.325 sq ft (2.75' x 6.3'). You need approx 86,625 lumens for that space. A 600W HPS puts out about 90,000 lumens. However.....with a space that long and narrow, the ends of the space will not be getting enough light. You will probably want to rotate your plants.

:yeahthat::goodposting:


I was thinking maybe a light mover instead of rotating? Have you ever used a light mover THG?

 

[Mikey09]

Thanks for the correction, i guess i could blame this all on THC... lol. I think i will try to go for a slightly smaller, more square room. Then put a 600W HPS in it. Thanks for clearing this up

 

[The Hemp Goddess]

:yeahthat::goodposting:


I was thinking maybe a light mover instead of rotating? Have you ever used a light mover THG?

Yes, I have one. If my space (6.5' x 3') is completely full, I sometimes run the mover so that the plants at the ends of the room get their fair share of light . It makes ventilation harder, however. I do not like to have to use flexible ducting (that droops) on my light, but if I have the light on a mover, I have no choice. A mover really makes the best use of your light in a rectangular space, however.

 

[pcduck]

Thanks THG I am with ya on that droopy ducting
I am thinking it may also work for me, at least during winter months when heat is not so much an issue.

 

[D3]

I use a light mover with a 1000w light. My room is long as well. Works great for me, no heat problem with the flex ducting. But, I have great air flow & a window unit that provides cool air over the grow.