How Many Wattz Do I Need?

potroastV2

Well-Known Member
The easiest way to think about it is when you are growing marijuana you will need about fifty watts of HID lighting per foot. This assumes that your garden is square, try to use this as a principal.

1 250 watt two foot by two foot garden.
1 400 watt for a three foot by three foot garden.
1 600 watt for a 3.5 foot by 3.5 foot garden.
1 1000 watt for four foot by four foot garden.

All you have to do to make that general rule work is line your walls with flat white paint or mylar to make sure your garden gets ample coverage, also try to make sure the lamp has a good reflector on it.

That should get you started :weed:
 

darryl

Active Member
if i have a 15 watt flourescent light and a 50 watt flood light over my plant is that enough for it to grow (in the vegetative stage)?
 

ViRedd

New Member
if i have a 15 watt flourescent light and a 50 watt flood light over my plant is that enough for it to grow (in the vegetative stage)?
Get rid of the flood light. It has the wrong color spectrum and pumps out way too much heat. The 15 watt floro is just barley enough to grow seedlings and cuttings with. See rollitup's post above.

Vi
 

Brainfreeze676

Active Member
grow using plant growth lights with a blue spectrum during vegetation cycle on a 18/6 light cycle. you want a 125 watt for begginers.it works fine and just have foil around the area and it will work fine..b careful of the temperature though keep it regular
 

Heliotropic chaos

Active Member
I once got my seedlings going on the window sill, with just an 11w CFL(one of those energy saving light bulbs).. It took a fair while longer than the 125w CFL I have now, but if ya skint and want to get some seeds on their way..

I think they were about 3 inch high after a month. That was in summer too, so maybe the best of it was from the sunshine. I totally support BrainFreeze sayin buy proper horticulture lights. This is my second grow with proper CFLs and the difference from shop lights is noticable in both growth speed and quality.
 

fat sam

Well-Known Member
if you went with a 250 mh or hps you would have 1 kick ass plant with some nice nugs, skip the cfl's if big gooey nugs are what you desire
 

mac17

Member
hey whats up im new on this so but i was wondering do u think its safe to buy seeds of the internet i live in northern california i need help
 

mac17

Member
hello there wats up hey well my name is luck i live in northern california well i wanted to khow on the rule of watts and feet is there a limit on how many plants i can put in a 3 by 3 foot space can u help me out
 
my first grow i used a 75 watt flood light i had it to high so the plant streched in lake of light i did one plant but it got to be 4 feet or more it was really crystaly but dont get the light to close it will get to hot and fry the top of it only 3 months in it had about an oz but for a first it was a nice one 70 watts is the lowest but you aren goin to haul as much with a lower watts higher the watts the fatter the plant i say
 
my first grow i used a 75 watt flood light i had it to high so the plant streched in lake of light i did one plant but it got to be 4 feet or more it was really crystaly but dont get the light to close it will get to hot and fry the top of it only 3 months in it had about an oz but for a first it was a nice one 70 watts is the lowest but you aren goin to haul as much with a lower watts higher the watts the fatter the plant i say
 
I

Illegal Smile

Guest
The sun puts 10,000 lumens per sq ft on a sunny summer day. Half that is great for indoor plants. I use cfls because of heat. My 2 sq ft bubbleponics gets 275w actual. That's more than needed. It is divided in veg with 190w 6500k and 85w 2700k. In flower that is reversed. Once beyond seedlings I keep lights 2-3 inches from plants.
 

MJ4ever

Member
so what U r sayin , is more light bigger better buds ???? cause im thinkin also on surronding , my plants with flourscent grow bulbs also all around the plants. would that make a difference, or would i just be wasting electric ?????

MJ4ever
 
so what U r sayin , is more light bigger better buds ???? cause im thinkin also on surronding , my plants with flourscent grow bulbs also all around the plants. would that make a difference, or would i just be wasting electric ?????

MJ4ever
More light is always better for the plant. Your plant will grow new limbs to use the new light and fill in. If yer not worried about the electric bill or cost of lighting, put as much as ya can.
 

r1tony

New Member
Yeah cram a 400 in there and fight heat like a firefighter for the rest of your grow. Great advice.
Ya I am in that situation now!! Was veggin with CFL (2- 26watt 6500k for each plant (2 plants)) and temps were low 80's. My closet is 48w x 40h and 26 deep and the temps since I fired up my 400watt HPS in there are 93-100 with 4" inline duct intake fan and 6" eco can fan pulling air right at light hood. I bought one of those little Stanley blowers to blow into my 4" duct fan and the temps dropped to high 80s to 90 but still tad high for me. Just becareful when you go you need a plan for heat dispersion.
 

thedude27

Well-Known Member
You can easily cool a 400 in that space, if you get a real fan. I was pulling 400 cfm in my micro grow on a 400 hps and a bunch of clf's with no cool tube and was easily maintaining 72-75. If you cheese out on the venting, yea you'll burn it up. With a cool tube you'd probably need 1/2 that. I just didnt have room for one.
 

Macinfo

Member
grow using plant growth lights with a blue spectrum during vegetation cycle on a 18/6 light cycle. you want a 125 watt for begginers.it works fine and just have foil around the area and it will work fine..b careful of the temperature though keep it regular
Is foil safe? I read the light refracting off of it can cause small burn holes in the leaves, and it's better to use plain white paper


@MJ4 think of it like this man - plants eat light, and they are some greedy fuckers. However much you give them, they'll just keep eating and growing. The only thing you have to worry about is keeping the temperature from the light down, too much heat can cause them problems.
 
Top