So, I am attempting to setup an indoor grow room in a 4x4x8 space.

My noob question is:

Will a 400w HPS be adequate to light this amount of space? If so, how many plants should I consider planting? (buckets with soil is what I want to use).

I'd don't want to necessarily 100% maximize the grow in this area since it is my first grow. But, what is the max amount of plants that can be grown in this space with a certain xxxW HPS light?

--Thanks.

No, a 400 won't be sufficient to light up a 4x4 space.

However, since you said you don't mind not fully maximizing your efficiency, yes, the 400 will be fine for a 3x3ish grow.

And the max amount of plants varies with your style and veg time - could go from 1 to 60 and everything in-between.

A good goal for you would probably be three or four solid plants.

__________________
Check out my journal for links to Youtube videos of my setup:

http://www.rollitup.org/grow-journals/250027-bubblelicious-new-york-power-diesel.html

i grow 4 plants under a 400w
i've done 6, but that many have to be kept small

__________________
"We shall not cease from exploration, and the end of all our exploring will be to arrive where we started and know the place for the first time." T.S. Eliott

I have the same size box and also have a 400 watt. I wish i went with the 600. I would go with six plants. My first grow **White Widow**w/pics i have six plants going right now check it out.

Thanks for the suggestions, I was actually hoping someone would say I should try 3-4 plants. That sounds manageable for me and would be a great first goal.

Any other suggestions with 3-4 plants with a 400 hps in a 3x3 or 4x4 space?

I am probably going to 18 inches and then start flowering....tentatively.

Thanks for the fast replies!


OH, and I forgot to add that I am having trouble finding good advice on a decent 400w HPS w/ ballast. Any suggestions?

HTGsupply - get an air-cooled hood if you can (you'll thank me later, especially in the summertime).

__________________
Check out my journal for links to Youtube videos of my setup:

http://www.rollitup.org/showthread.php?t=250027

Thanks Bob, I found a few good ones from HTG. So one reflector with that one 400w bulb is all I need in terms of lighting for the setup above? I have heard anywhere from 6-12 inches above the plant with this type of lighting. Does it matter how far away it is or is the distance from the plants only dependent on temperature/direct heat?

There's an inverse relationship between distance from the plant and the usable lumens that are available to the plant - as close as possible without burning the plant tips is where the light should be.

__________________
Check out my journal for links to Youtube videos of my setup:

http://www.rollitup.org/showthread.php?t=250027

Sounds good to me. One last question....for now . At what distance should the light be for germination, and is it easier to just use a CFL for germination if I have one?

I disagree and agree with bob smith. 3-4 plants is a good goal, and a 400 watt is just dandy for a 4x4 space. Two ways you can calculate sufficient light. 25 watts per square foot or 3,000+ lumens per square foot. This is minimum ratings for a happy plant, the more the better during flowering. Any experienced grower will tell you 3k/sq ft is sufficient for veg

400 watts.
4W x 4L = 16 square feet.
400/16=25 watts per square foot

400 watts
HPS = avg 127 lumens per watt (some do better than that)
127x400=50,800
50,800/16=3175 lumens per square foot.

There are a few options when you're going to purchase. If you want to go Metal Halide for veg then HPS for flower, you can get a digital ballast or a regular ballast. Difference is, digitals can run any bulb you put into them (except conversion bulbs, they get pissed) and with a regular magnetic ballast you'd have to buy a MH conversion bulb.

I'd go with either
400 watt digital ballast with mh and hps bulbs
OR
600 watt magnetic ballast with HPS bulb and MH conversion bulb

Either way you're going to run into heat buildup problems. You can veg under HPS, and if that's your decision there is a great option. The Son Agro 430 watt HPS bulb. Plugs into a 400W ballast. 400 watts of HPS light with an added 30 watts of blue spectrum light to promote vegetative growth during flowering. I've got one, they kick ass

I've done alot of work with both 400 watt and 600 watt lighting systems in a similar sized space to yours. PM me if you need any more help, I'm not the best at tracking threads

-Grizz

__________________
Grizzly and Smokey be friends my friends

Its not a beard, its a face trophy