cheap CFL's

i'm not sure if they are at every walmart (i live in dallas) but the one i frequent has 23W CFL's for $.92. i'm not sure of the spectrum and the like but you can't beat the price either way. just thought i would share. hope this helps some of you out.

-shake

why are my lights putting out so much heat? 2 are 26 watt general electric general purpose energy smart bulbs that puts out 1750 lumens a piece and i have a 30 watt sylvania soft white mini 100+ which puts out 2000 lumens. I thought flourescents were supposed to be very cool compared to hps/mh and it was safe to have your plants 1-2cm away from the light. also what are led lights?

if u didnt realize it i'm using cfl's. also the 26 watt spiral bulb is/are $1.00 while the 30 watt i paid $10 for sadly enough

Quote:

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Originally Posted by darkdestruction

why are my lights putting out so much heat? 2 are 26 watt general electric general purpose energy smart bulbs that puts out 1750 lumens a piece and i have a 30 watt sylvania soft white mini 100+ which puts out 2000 lumens. I thought flourescents were supposed to be very cool compared to hps/mh and it was safe to have your plants 1-2cm away from the light. also what are led lights?

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hey guy, as a fellow CFL'er i thought i'd take a stab at answering your questions.

in answer to your first question, CFL's actually run hotter than HID, watt
for watt, the advantage is that the heat is spread throughout the grow
room rather than concentrated at one very hot point.
because it's spread out, it's easier to deal with.


also, 2 - 3 inches from the plants is a good rule of thumb, not 1 - 2 cm's.

LED's are Light Emitting Diode's and they're way more efficient than either
CFL's or HID's, unfortunately, they're still very new technology so they are
still working on them.

a few more years and and we'll all be using them, go take a look at these threads
if you're interested in LED's

http://boards.cannabis.com/grow-log/...-grow-log.html
http://boards.cannabis.com/indoor-li...row-light.html

Ok, here's a little rant about CFL bulbs that you might find useful... or not... but here's a little rant none the less:

These 23 Watt bulbs have a very very limited effective depth of penetration - keep in mind the inverse square law: very simply, the effective lumen output of the bulb, the amount of light actually reaching your plants is 1/4 as strong at 2x the distance. E=I/R^2 where E=light intensity, I=initial intensity at the point source, and R=radius from the point. So your light output is divided by the square of the distance - inverse square law.

Now, as justanotherbozo pointed out, CFL's actually put out more heat per watt than HPS/MH bulbs. In order to use very very low wattage bulbs like that, you would have to use a lot of them very close to the tops of the plants. You also have to keep the plants very very short - the effective depth of light penetration is very shallow therefore you are trying to keep your buds short and compact and within this effective range where they receive enough light to grow nice and full - part of that range being the space between the tops of the plants and the light.

CFLs work fine, but 23watt bulbs are about the smallest and lowest intensity you can get - they're fine for a reading lamp, but maybe not so appropriate for growing nice big juicy buds. There's nothing wrong with using them for veg, but you want more light depth in bloom.

Like I said those tiny bulbs are fine for veg - but in bloom light intensity actually reaching the plants is just about the most important factor in your final yield (assuming no other factors are totally out of whack) - Your plant in bloom is a solar powered bud factory.

I am currently using four 42 Watt CFL bulbs in bloom, each is about 2 - 3 inches above the plants (errr... plant at the moment as I only have one in bloom right now). Even for my TINY bloom space (18" deep by 30" wide if memory serves... it's night time in there now so I can't measure at the moment) This is about the ABSOLUTE minimum I would go with - most people would say this is far below the minimum really, but it's just barely enough that I always have herb around to smoke. I plan to upgrade when my highly stressed budget allows possibly adding a couple 105 watt CFLs or maybe a small HPS light.

Those 23/30 Watt bulbs will work fine for veg - I've found 5,500k color temp bulbs 23 watt bulbs that I'm running in veg now and they work fine, but I'm also keeping my plants small - under 6" high by topping/fiming and obsessively wire training all the way through veg. (Which is kind of fun actually.... there's something satisfying about harvesting a plant that looks like a cross between an upside-down chandelier and a menorah - some year I want to grow a perfect menorah and give it to one of my herb smoking Jewish friends)

For bloom, you'll want something around 2,700k temp - and you will want to grab the highest wattage bulbs in that color temp that you can get - which happened to be 42 Watt where I'm at :-( If you can find 55 Watt CFL bulbs on the shelf close to 2,700k color temp so much the better.

And forget whatever incandescent equivalent these things are advertised as - you know "120 watt replacement, only consumes 32 watt" that means absolutely nothing. Actually it means LESS than nothing because it causes a whole lot of confusion - what they are really saying is "32 watt bulb that produces the same amount of light as a really really horribly inefficient and crude design would if it were sucking down 120 watts" Incandescent bulbs aren't even in the discussion, so don't let them fool you by using incandescent equivalent. An incandescent bulb uses that much juice because it pumps out more heat than light - we don't care how much power an incandescent bulb would have used in producing heat - we don't want heat, we want light.

Quote:

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Originally Posted by IAmKowalski

Ok, here's a little rant about CFL bulbs that you might find useful... or not... but here's a little rant none the less:

These 23 Watt bulbs have a very very limited effective depth of penetration - keep in mind the inverse square law: very simply, the effective lumen output of the bulb, the amount of light actually reaching your plants is 1/4 as strong at 2x the distance. E=I/R^2 where E=light intensity, I=initial intensity at the point source, and R=radius from the point. So your light output is divided by the square of the distance - inverse square law.

Now, as justanotherbozo pointed out, CFL's actually put out more heat per watt than HPS/MH bulbs. In order to use very very low wattage bulbs like that, you would have to use a lot of them very close to the tops of the plants. You also have to keep the plants very very short - the effective depth of light penetration is very shallow therefore you are trying to keep your buds short and compact and within this effective range where they receive enough light to grow nice and full - part of that range being the space between the tops of the plants and the light.

CFLs work fine, but 23watt bulbs are about the smallest and lowest intensity you can get - they're fine for a reading lamp, but maybe not so appropriate for growing nice big juicy buds. There's nothing wrong with using them for veg, but you want more light depth in bloom.

Like I said those tiny bulbs are fine for veg - but in bloom light intensity actually reaching the plants is just about the most important factor in your final yield (assuming no other factors are totally out of whack) - Your plant in bloom is a solar powered bud factory.

I am currently using four 42 Watt CFL bulbs in bloom, each is about 2 - 3 inches above the plants (errr... plant at the moment as I only have one in bloom right now). Even for my TINY bloom space (18" deep by 30" wide if memory serves... it's night time in there now so I can't measure at the moment) This is about the ABSOLUTE minimum I would go with - most people would say this is far below the minimum really, but it's just barely enough that I always have herb around to smoke. I plan to upgrade when my highly stressed budget allows possibly adding a couple 105 watt CFLs or maybe a small HPS light.

Those 23/30 Watt bulbs will work fine for veg - I've found 5,500k color temp bulbs 23 watt bulbs that I'm running in veg now and they work fine, but I'm also keeping my plants small - under 6" high by topping/fiming and obsessively wire training all the way through veg. (Which is kind of fun actually.... there's something satisfying about harvesting a plant that looks like a cross between an upside-down chandelier and a menorah - some year I want to grow a perfect menorah and give it to one of my herb smoking Jewish friends)

For bloom, you'll want something around 2,700k temp - and you will want to grab the highest wattage bulbs in that color temp that you can get - which happened to be 42 Watt where I'm at :-( If you can find 55 Watt CFL bulbs on the shelf close to 2,700k color temp so much the better.

And forget whatever incandescent equivalent these things are advertised as - you know "120 watt replacement, only consumes 32 watt" that means absolutely nothing. Actually it means LESS than nothing because it causes a whole lot of confusion - what they are really saying is "32 watt bulb that produces the same amount of light as a really really horribly inefficient and crude design would if it were sucking down 120 watts" Incandescent bulbs aren't even in the discussion, so don't let them fool you by using incandescent equivalent. An incandescent bulb uses that much juice because it pumps out more heat than light - we don't care how much power an incandescent bulb would have used in producing heat - we don't want heat, we want light.

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LOL, what he said! i mean, for real, i agree with every single word

this post should be required reading for any noob's out there trying
to figure out how to grow they're own without spending a ton of dough.

CFL's make it cheap enough for someone to try growing without having
to invest several hundred bucks.

once you become self-sufficient, you can use your savings to buy
better equipment

has anyone seen those colored CFL lights? something like this. would these do anything at all beneficial or is it more a just a party gimmic? i looked through several websites and couldn't find the color temp for any of them. maybe it's the same as the same watt regular version and is just painted or power coated over?

any thoughts?

-shake

Those are useless - you want two different light spectrum's: Veg @ around 6,500k - I'm actually using 5,000k or maybe they are 5,500 not sure and it seems to be fine, and Bloom: @ around 2,700k. Try to target those light colors - don't bother with tossing in oddball party lights and such.

Those colored lights are just for parties, mood lighting, or college kids' dorm rooms. That being said, the green ones MIGHT be useful as safe lights if they eliminate enough of the outside spectrum. Leaves are green because chlorophyll REFLECTS the green spectrum - it isn't absorbed and used by the plant. What this means is that a pure green light can be used if you absolutely have to enter your bloom chamber to check on your plants during their dark period. If it removes enough of the non-green spectrum then it won't disrupt their sleep, at least for short periods of time. I've never tried this, but I do know that there are actual green safe-lights sold at garden centers and online.

Quote:

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Originally Posted by headshake

has anyone seen those colored CFL lights? something like this. would these do anything at all beneficial or is it more a just a party gimmic? i looked through several websites and couldn't find the color temp for any of them. maybe it's the same as the same watt regular version and is just painted or power coated over?

any thoughts?

-shake

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The color temps are listed - the link you posted was to 1000bulbs.com, look under standard fluorescent bulbs. You'll see that they are divided up wattage.

Here's what it has to say about the first light listed in the 42 watt category:

# Manufacturer: Neptun
# Manufacturer's Part #: 24542
# CFL Spring Lamp
# Non-Dimmable
# Wattage: 42 Watt
# Incandescent Equivalent: 200 Watt
# Voltage: 120 Volt
# Initial Lumens: 2,800
# Operating Temp (Min.): 0° F
# Operating Temp (Max.): 120° F
# Life Hours (Avg.): 8,000
# Base Type: Standard Medium Base
# Color Rendering Index (CRI): 82
# Warm White 2750K Click Here
# Overall Length: 6.75 in.
# Overall Diameter: 2.88 in.
# Features Amalgam Technology
# 12 Month Warranty
# UL Listed
# Case Quantity is 24
# Price Shown is per Bulb

You need to worry about two numbers: First, initial lumens - this one is 2,800 initial lumens. The second is color temperature: This one is 2,750k which places it in the red spectrum ideal for bloom.

Thanks for the insight man. You seem very knowledgable in this area. It helped me out in deciding what lighting to go with. Initially I was going to used 26 watter 2700k with y adapters to have 6 of em for flower and have 10 more watts than using 3 42 watts, but now i know that the 42 watts will be more efficient.

Again

Thanks