100 watts per plant? Veg

[Lester Freeman]

When people say 100 watts per plant is a minimum, do they mean the incandescent equivalent, or the amount of watts being used?

I have two 23 watt CFL lights, which converts to 200 watts of equivalent light. That should be enough to vegetate 1 or 2 plants right? Using a 5500K color temperature..

If they mean amount of watts being used, then I'm way off at 46 watts, LOL

 

[Lester Freeman]

If lumens per plant, how many lumens per plant would be a minimum?

 

[Hosebomber]

Lighting should be used as a coverage and not per plant. I'm American so I'll give the standard numbers for the flowering stage as follows:

CFL lighting (to include T5, T8, and T12) = 65 watts per square foot.
HID (MH, CMH, or HPS) = 50 watts per square foot.
LED (there are some exceptions to this and it is a complex situation, but in general) = 35 watts per square foot.

Remember that the LED panel needs to have the correct spectra to use the reduced power efficiently. Therefore, I say 35 watts of a quality manufactured LED panel.

Lumens is a measurement of brightness to the human eye. Wavelengths that are used relatively less than any other rates the highest in this measurement system. PAR rates the wavelengths that plants use more higher and is therefore a better measurement of light output to use.

 

[Lester Freeman]

Cool thanks mate.
Do you mean 65 watt's of generated light, or 65 watts of used energy?
The CFL I have says it uses 23 watts, but it equates to 100 watt's for an incandescent.
Since I have two, does that only make it 46 watts? Does the equivalency matter?

Sorry I am just a bit confused on what these conversions mean

 

[Hosebomber]

Watts are a measurement of input power. For CFLs that means the amount of power drawn, not what they equal in incandescent lighting.

 

[cgkone]

pretty smart, but is that a minimum # for the LED.Also, dont you have to consider depth of the space, not just hieght and width?

 

[Hosebomber]

Yes, those are minimum numbers for all lighting types. Increasing the amount of light beyond that will only increase production up untill the light saturation point. You get lighting to fit the space requirements. Depth is not considered because you can increase or decrease the height of your lights as needed... This is only a true concern when you have little head room and want a higher wattage. You cannot place HID lighting close to your plants due to heat issues and some bleaching. LEDs will not "burn" your plants only bleach. If you are growing 5ft + trees in your area you will need side lighting regardless of what lighting option you chose.

 

[cgkone]

i was referring to the third mesurment to achive a cubic foot measurment. But i understand what your saying and thats a minimum forsure. i got roughly 250 watt output of LED covering my 2x2 space and thats maxing out my light saturation..... would you agree?

 

[Hosebomber]

Without knowing the exact spectra wavelength output of the light that is very hard to give an exact answer. Likewise, If the LEDs have a secondary optic on them it would change the calculations as well. Depending on the exact wavelength (plants use different wavelengths in different amounts), light saturation generally doesn't occur below 1500 micro mols. So to answer your question, No you are probably not near the saturation point.

 

[Lester Freeman]

Hose, I have 6260 lumens that is a mixture of 2700 K and 5500 K light covering a 2ft x 2 ft area.
I am attempting to vegetate 2 small plants under this amount of light until the Spring comes, and then I will put them outside to finish.
Is this an amount of light that is not nearly enough, reasonable, or enough?

You the bomb

 

[Hosebomber]

Lumens are a poor measurement of light output. It is skewed toward the human eye sensitivity scale and does not reflect the amount of photons being released, the density of those photons, or the wavelengths represented.

I'm guessing that you are using four 23 watt T5 shop lights bulbs?

If that is correct, then you are giving them enough light to survive but not enough to grow properly. Small lighting such as that is used to keep mother plants dwarfed in a vegetative state. You would be better served with 3 5500K+ CFL bulbs and 1 CFL 2700 Kelvin bulb dirrectly over the pots with them being as close together as possible. As the branches start touching each other spread them apart slightly and add another 23 watt CFL for every 4-6 inches you move them apart from each other. Try to keep the lights within 6 inches of the top after they get their second or third set of true leaves.

 

[Lester Freeman]

OK Awesome, thanks a lot my friend.
If I can figure out how to send rep points, they'll come your way!

PS. I'm using one 55 watt CFL (2700 K ) directly above w/ plants as close together as they can. And two 23 watt CFL's (5500K) that are shining light at a 90 degree angle from the side.

 

[cgkone]

if you live in cali and your starting plants now that you want to finish outside your WAY ahead of schedule. you will be ready to harvest couple months into the outdoor veg. But my lights cover 2 reds one blue and 10k white. im not talking about a stop light or some bullshit light like that. this is well built just for growing plants

 

[Lester Freeman]

I haven't planted the actual seasons seeds yet, But I have a couple of plants going as an experiment.

 

[undecided]

Hell all those numbers may mean something, I say KEEP IT SIMPLE 8 bulb t-5 HO works fine on 10 plants. I know that aint no 100 watts a plant. Sure works good for me though, and Im sure many will agree.

 

[reparboon]

i veg under 6 40w t12 OD (comes to a total of around 350 watts) and i find it very effective for the 4x2 space it covers.(my plants grow as good as a MH) 2 mothers and around 25 veg plants at all times. in 3 weeks from rooted clone when i first put them under the od t12 till they hit the bloom room they grow on average 14 inches with alot of foliage. why go out and spend 150-400 on t5 bulbs and hoods when you can overdrive a t12 or t8 bulb for a fraction of the price and get the same results. it cost me $64 and around 1 hour to build.

 

[undecided]

Seems to me the thing to do is buy an American made T5 light and bulbs instead of cheaping out on a bunch of Chinease made junk. Again, you are growing a product thats almost worth its weight in gold. Maybe you arent gretting the great results you talk about, or you had to start out that way and have your mind stuck in that mode. Puts some Americans to work, and BUY AND GROW AMERICAN.

I rest my case

 

[The303Stoner]

I guess you might have miss the max Yield Light Issue. I didn't! Read it if you can find it. Anyway you can get a 15 ft. mogle socket to reg 120 3 prong cord and A 150w grow bulb $40+ 200W $60+ 250w $80+ 300w $100(you get about a foot per 100w)if your in a closet this kick ass) 10,000 hr life and the bulb star to turn black so you know that they are old. they dont get hot. they come in red, bule and now full. A one year warranty your good.

 

[reparboon]

LST and primming get you alot of foliage no matter what light you have... add a screen and even more. make the plant your bitch and do as you please it to. #YODA

 

[1Oldgoat]

My setup is akin to Undecided's.... (8) T5 HO's and a couple drop down 125 W CFL's to augment. Working just fine in the flowering area. Could not use HID's because of heat factor; You can get REALLY good results with CFL's and HO T5's.... Keep em short and figure out a cloning schedule for a perpetual micro harvest. Keep the Ideas coming guys.... I am always tweaking !!!