CFL lighting 101

cyberquest

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ok so your new here and you seen everyone using CFL (compact flourescent) lighting and you have tons of questions. should i get bright white, cool white, warm white? fear not my freind cause i am going to cover with you a few of the basics of CFL lighting. :)

first lets talk about their wattage, most CFL are energy savers, this is a added bonus. a 26 watt CFL is compairable to a regular 100w incandecent bulb, puts out the same amount of light , it just uses lower wattage. common sense tells us that the higher the wattage the more light it puts out, so yes you want to find the highest rated light you can.

second each bulb also has a lumens rating, this is a measurement of percieved value that our eyes see, the higher the lumens, the more light it produces. when you choose your bulbs make sure you find the one with the highest lumens output, this should be listed on the package.

third we have color temperature spectrum, better translated as Kelins, each bulb has a kelvin color rating as well, and this will be one of the most important parts of choosing your bulb! plants need light in the lower temperature scale to simulate the summer months for veg, and they need a higher temp spectrum of light for flowering. some packages are marked with the color spectrum as well, some are not, you might have to get on the bulbs web site to find out more info. if it is marked on the package it will be rated like this: 2700k ( the k stands for kelvins) 3000k, 4000k, 5000k, and so on and so forth.

Just as humans need a balanced diet, plants need balanced, full-spectrum light for good health and optimum growth. The quality of light is as important as quantity. Plants are sensitive to a similar portion of the spectrum as is the human eye. This portion of the light spectrum is referred to as photosynthetically active radiation or PAR, namely about 400 to 700 nanometers in wavelength. Nevertheless, plant response within this region is very different from that of humans.

The human eye has a peak sensitivity in the yellow-green region, around 550 nanometers. This is the "optic yellow" color used for highly visible signs and objects. Plants, on the other hand, respond more effectively to red light and to blue light, the peak being in the red region at around 630 nanometers. The graphs below show the human eye response curve and the plant response curve. Note the vast difference in the contours.




so seeing the above charts tell us that a bulb that is best rated for our eye, isnt even close to what is going to get the best response from the plant. so we need to keep this in mind when buying ANY bulb not just CFL lights. you can see the plants peak sensitivity is at 425nm and 625nm, so if you research your light to fall into these peak spectrums of light your going to get bigger yeilds from your plants. our eyes are peak sensativity is at around 575nm so a bulb that is used to give us peak lighting isnt what is best for out plants.


ok your still with me, but maybe your a tad confused with all the technical mumbo jumbo. lets give you another scale to maybe help understand a little easier.


here you can see the K relation on the NW scale, notice the curve of each color temperature spectrum and how much different they are.

the bottom K numbers are scales to represent colors of light that we see (K).

9300K = sunlight rated bulbs
6500K = bright white
5000K = soft white
3200K = warm white

you can see on the scale above each lights color temp spectrum in relation to the NM color spectrum that plants see. plants peak sensitivity to light is 425nw for vegatative growth, so which bulb above would be best for our plants? if you answered 6500K get up go to the kitchen and get yourself a cookie cause you did good;) so this tells us that a 6500k bulb would be best suited for us to use to grow seedlings in their veg stage.

REMEMBER this about the K scale, this is a scale set and used by the light industry to give ratings to bulbs based on what is best suited to our eyes!

this above scale isnt a good scale to choose our flower bulb with cause its a rough scale of the basic standards set by the light industry.

so how do i choose my flowering CFL bulb, well best i can say is with research, here is a example of a bulbs output as provided by its manufacturer.

here is a graph on a Sylvania 30w CFL, 1700 lumens, rated at 3000K

bulb specs: 1700 lumens 3000k
you can see that the bulbs peak output is right around 625nm, and where is our plants PEAK sensitivity for flower at? same as this bulbs peak output, so this bulb would be great if you are going to flower with a CFL bulb.

ok so you now have a basic understanding of what CFL bulb you are looking for, but i will tell you know that finding a 6500k CFL is gonna take some searching, WHY? because our eyes are more sensitive to the 575nm range, which is in the warm white bulb range, so 90% of CFL bulbs are going to be in this range because it will APPEAR brighter to our eyes. but at the end of this topic i will give you a link to some SUPER awsome CFL bulbs so dont worry, i got you covered ;)

now we need to talk about something else, LIGHT INTENSITY. this too is very important for growing plants! Light intensity diminishes the further it has to travel. This is the same for HID, CFL or your normal household lamp. If you hold a light meter up close to any lamp and then slowly lower the meter, even a few inches, you will see the light measurement reduces dramatically.

so what does this tell us? the farther the bulb is away from the plant, the less intense the light is to the plant. light intensity reduces by half for every foot it is away from the plants. So if your bulbs are a foot above your plants much of the light is wasted or lost. not to fear though because a CFL produces much less heat then a HID bulb (MH & HPS) so you want the bulb as close as possible to the plant without burning it so that you arent loosing the intensity of the light.

that being said i want to talk about HID lights for a second. The problem with HID lamps is they are so hot you cannot place them close to your plants. a 400w HPS bulb is recommend to be at least 22 inches above the plant, and remember what you just read about light intensity at a foot away, so at 22 inches your almost two feet away from the plant much of the light, and your money, is wasted. there are special cooling hoods avalible for HID bulbs that help keep them cool, and if your using a HID lamp you need one so you dont loose the intensity of your light.

In the past fluorescent lamps were always known to have excellent 'daylight' colour output but not the same photon power as HID / HPS lamps. The spectrum from fluorescents was ideal for propagation/seedlings but not for real time growing, because they were small watt versions and did not have the lumen / photon output. (i.e. an average household fluorescent tube is only about 35 watts. Nice spectrum but low light output! )

The development of high-output compact fluorescent means you can now get the correct colour spectrum, always associated with fluorescents, but with much higher light output. This means that CFL's are now capable of much, much higher lumen output with all the benefits of the ideal, spectrum output.

Photon strength is still not as strong as HID Lamps (although with our new reflectors we are getting there) but because these new lamps generate much less heat they can be placed just inches of the leaves, and this is a very, very important factor when using grow lamps so that you dont loose your light intesity.
 

cyberquest

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ok now we are really gonna throw you for a loop. we have stated above that LUMENS is a rating set bu the lighting industry to give us a scale of measurement of light to our eyes. BUT what is the scale of measurement for the plant? this measurement is called PGL (plant growth lumens) and is a more accurate measurement of light seen and used by the plant. so in all reality, LUMENS means aboslutly NOTHING to the plant, cause it doesnt see human lumens as rated by the light industry scale. it sees PGL which is actual lumens to the plant.

here is an example of humen lumens in compairison to PGL of a CFL bulb.

20w CFL is rated at 1200 human lumens.
The PGL of a 20w CFL is 841.
this means that the plant sees 70% of PGL in compaison to HUMAN lumens.

now lets take a look at a MH bulb.
50w MH is rated at 3000 HUMAN lumens.
the PGL of a 50w MH is 1890.
this means that the plant sees 63% of PGL in compairison to HUMAN lumens.

now we look at a HPS bulb.
35w HPS is rated at 2240 HUMAN lumens.
the PGL of a 35w HPS is 1534.
this means that the plant sees 68% of PGL in compairison to HUMAN lumens.

so for all you people that have a 400w HPS (myself included) which is rated at 55,000 lumens this means that the plant is only actually getting and USING 68% of those HUMAN rated lumens. so 68% of 55,000 lumens is 37,400 PGL. BUT lets also take into consideration what i mentioned above about LIGHT INTENSITY, that HPS light is 22 inches away from your plant. so our actual lumens is cut in half for every foot, so is the PGL, meaning that the 55,000 lumens HPS light is actually only 11,500 HUMAN lumens because we are almost two feet away. which also means that the PGL is cut down for every foot of distance meaning that the ACTUAL plant PGL is now only 9350.

what does this mean? it means that you thought you have 55,000 lumens in your your grow room, and YOU DO, looking at it with your HUMAN eyes. BUT, thru the plants eyes so to speak, its only seeing the 11,500. and you have done all your math based on HUMAN lumens.

so your 4x2 grow room has 8 sq ft. 55,000 lumens divided by 6 = 6875 HUMAN lumens per sq ft.
BUT in all reality its 37,400 PGL divided by 8 = 4675 PGL sq ft.

but since your light almost two feet above your plant we have to cut that by half for every foot of distance, which gives us 1168 PGL per sq ft. so are we really acheiving our goal of 6000 lumens per square foot with our HPS, as measured in HUMAN lumens we are, BUT in PGL we are NOT!!


now back to our percentage of efficency of human lumens to PGL.

CFL = 70%
MH = 63%
HPS = 68%

we see by this that the CFL bulb has the highest percentage of HUMAN lumens to PGL. so this actually makes it the most EFFICENT of the three bulbs.

AND since we cn place our more efficent CFL bulb right on top of out plants this means that our light intensity is actually greater also!

so lets figure my CFL room like we did my 400w HPS.
i have 12 26w 1600 lumens bulbs, all evenly spaced over the entire 4x2 encloser not just concentrated over the very top but more evenly spread over the canopy.

so i have a total HUMAN lumens output of 19,200 lumens divided by my 6 sq ft = 3200 HUMAN lumens per sq ft. (within the acceptable range of 3000-4000)

but as stated the plant only sees 70% of that so the PGL = 13,440 PGL divided by 6 = 2240 PGL

SO we see in all reality that the CFL room is MORE EFFICIENT at providing ACTUAL PGL TO THE PLANT!!!!!!!!!!

AND we are doing this only using 312 watts as opposed to our 400watts it takes to run our HIGH powered HPS light.

so unless you can COOL down your high powered HPS bulb enought to drop it down to a 4 inch distance that the CFL can be at, the CFL can be a MORE EFFICIENT , COST EFFECTIVE, light for your grow room.
 

cyberquest

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take a look at some of these new CFLS!

so you think a CFL cant put out enough lumens huh?

this is a 300w, 21,600 lumens CFL, that was designed to replace MH bulbs! it had the equivalant of a 1500w bulb! at only 300w of power mind you. only avalible in the 5500K spectrum.
http://www.uswaycorp.com/CFL.htm




these ones use a ballast just like a MH or HPS but again only 300w of power and the output of a 1500w bulb.
http://www.azeehydro.com/nurturelite.html


this is the envirolite, not quit as powerfull as the ones listed above but they are rated at 6700k (veg) and 2700k (flower)

http://www.envirolites.co.uk/lightinfo

look to see more and more CFL grow bulbs popping up, cause it looks like this might be the new age of indoor growing;)

this one requires a mogul based socket like a MH & HPS but doesnt need a ballast, its ballast is self contained, it just uses the larger socket.

http://www.plantlightinghydroponics.com/grow-bulbs-fluorescent-c-73.html
 

pussum

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So what would be a good bulb to get if you are just starting out? I guess you need two sets as one would be for flowering and the other for veg. So just name off something that will do the job. Nothing to complicated or detailed. Just something to start with.

P.S.- Lots of great info. Keep it up!
 

cyberquest

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This one would be awsome!
http://www.topbulb.com/find/Product_Description.asp_Q_intProductID_E_49655

although way more pricey then your average bulb, but its a 6500k bulb and it 6750 lumens, would be a great veg bulb.

this is gonna be the next part to this post i hope, like i said way up at the top there finding a 6500k bulb in your average department store is going to be tricky cause most of them are going to be warm white cause its what APPEARS brighter to use cause its color spectrum is in our peak sensitivity range.

i know last time i was at lowes i saw a full spectrum bulb, full spectrum means absoluty nothing really except they call it special and charge more, but its a much blue array of light so i want to do some more research.

i hope to find and track down these harder to find bulbs so i can give everyone links on where to get them.

i finished this topic at about 4am my time so i am pretty tired today, but in the name of MJ i must push on!
 

T-Bone

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This is a truly awsome post and should be here forever. thank you
~T-Bone
 

cyberquest

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ok looks like home depot has some good ones.



Philips 27w 1750 lumens 2700k $10 for a two pack.



Philips 27w 1660 lumens 6500k $13 for a two pack.
 

cyberquest

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while i was out at wal-mart today getting some pots i browsed thru the lighting section and ran across these and picked them up.

26w 1600 lumens 6500K ;) price : $6.44


here is the 6500K next to a 2700K , you can see the yellow/orange color of the 2700K and the blueish color of the 6500K. i have two 6 light bars in there, my goal is to have 6 2700k and 6 6500k when its all done.
 

Brouli

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CQ i use 2 26watt that put down 1750
 

T-Bone

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that looks like a nice set up. and i saw those lights at wayy world a few hours ago, thats f-ed up i was gonna post about those.
~T-Bone
 

cyberquest

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good find ;) thats a mogul base bulb though, just like the MH and HPS use, and i cant tell if its self ballast or not. good price and good lumen output though.
 

Brouli

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they dont use ballast i check with a guy in store thats the beauty of it .


CQ so if i run 302 watts
that 4 of those and and regular 42 watt CFL
tahat 29500 lumes in a room 2x3 that 4916 lumes per square feet is that good for good yeld ??
 

cyberquest

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your right about on the money, they say 5000-6000 for best results and your just a hair shy so i would think you would see great results.

AND with that light not being all packed into one unit you can place them at different areas in the grow room to give you more even light within your grow room.

i have thought about making a small box myself for veg with four of those similar lights, placing one in each four corners. i think that would give and awsome grow cause the light could hit all areas of the plant and not just the top.
 
G

g-13

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i have 2 600w hps. so u mean to tell me i wasted my $ and could of been growing with lights from walmart all along. that hydro store really stuck me on those lights too.
 

cyberquest

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no thats not what i am saying, i too use a 400w hps for flower. what i am saying is that the farther away it is the less value it is to the plants. the cooler you can get the light the closer you can get it and the more value it will have on the plant. HPS still has very good penetrating values.

my plans for mine are to upgrade to a cool tube, they are 6inch tubes that house the light and allow you to install a fan on both ends, one sucking in , one blowing out, this way it will keep it super cool and allow you to drop it within inches of the plant.

how far are your lights away from the plants?? 600w is 95,000 lumens if i am not mistaken. i know that my top of plant temps at 22 inches is around 90 degrees, any closer and it would fry them because of the heat. so if you are 24" away lets say, you loose light intensity for every foot you are away by 50%, so at two feet its cut in half, then half again. so at two feet away the light intensity is only at 23,750 lumens so to speak. times that by two lights you have for a total of 47,500 lumens at two feet away with two 600w HPS.

its would take 30 CFL bulbs at 1600 lumens each to get that much light to the plants. thats about your average lumens of a wal-mart style 100w equivelent CFL.

the point of me making this post is that the technology of CFL's is increasing, they are producing more lumens then when they first came out, and are making there way into the horticulture scene very fast, and wont be long before we have mega lumens grow lights capible of produce the lumens of the HID lights.

the thing that makes CFL's favorable is that you can get them close to the plants like flouros, so your not loosing you light intensity making them more efficent ONLY because they can be placed closer to the plants.

trust me when i say those two 600w HPS are gonna give you some kick butt buds!
 

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