CFL Light Tutorial

Blitty D said:
Roseman,

After just getting my electrical bill and noticing that 1000wt is costing me $80 per month, I am suddenly very interested in using CFL's for my next bubble crop! I live near a homedepot and a hydro shop, im guessing HD will have better prices? what should the total cost be for all the CFL's i would need be?
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You can get 65 watt bulbs for $16 at Lowes and Home Depot, and a mogul one for only $9. 42s are $8 and $9 everywhere.
let me know the total SQ Footage of the grow area and I will help you calculate how many watts/lumens you need.
 
Blitty D said:
The grow area will be the same one as in my journal, roughly 2x3x5.
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OK, let me go over this with you.

You have 6 square feet (2 X 3) of growing space. (way too little for those 1000 watts)

Ok, lets read this together:



How much light is needed for growing?
Depends on the size of plant you are trying to grow. I'll try to answer this "in general" instead of being specific to one size plant. Light seen and perceived with the human eye is measured in Lumens. There is an ideal amount of lumens for growing and a minimum amount of required lumens. The very minimum amount of light required for smaller sized plants grown is around 3000 lumens per square foot. Let me put emphasis on "minimum amount" of light. However, that's not 100% exactly accurate, since although you may have a 10,000 lumen light, the amount of light that reaches the plant varies with the distance between the light and plants, and the reflectivity of the grow area. The ideal amount is somewhere around 7000-10,000 lumens per square foot for average sized plants. As long as the plants do not show burn, as much light can be used as you want to use. (Note, the sun produces about 10,000 lumens per square foot, on a sunny mid summer day).
Contracy to "talk" you CAN have too much light.)

Determining lumens for your grow area:
First determine the square footage of your area (example in a 4 foot by 4 foot area, there is 16 square feet, 2 by 2 feet is 4 Sq ft. ) If you have a 1000 Watt High Pressure Sodium Light Bulb, that produces approximately 107,000 lumens. Divide this by 16 (your square footage) 107,000 divided by 16 = 6687 lumens per square foot. So just divide the total amount of Lumens, by the total amount of square feet, and that's your lumens per square foot.

The ideal amount of lumens needed is at least 7000 per Square Foot. 6 Sq Ft needs 6 X 7000 = 42000 lumens at least. 60,000 lumens at Most.

Now if you go with 65 watt CFLs...........
you will get 60 to 70 lumens per watt. Let's say 70 lumens per watt, you need 42,000 lumens, so divide 42,000 by 70 and you need 600 watts of CFLs. Divide that by a 65 watt bulb, you need 9 65 watt bulbs. With ten 65 watt bulbs, you'd be very ample.

Divide them into half 2700 k and half 6500k, and you 'd be perfect. Cost you about $10 to $16 a month to burn them.
 
How do you factor in the height of the light away from the plants with this? Because sometimes my 1000wt would be about 3-4 feet from plants, when I got it within a foot I noticed some scorching........
 
Blitty D said:
How do you factor in the height of the light away from the plants with this? Because sometimes my 1000wt would be about 3-4 feet from plants, when I got it within a foot I noticed some scorching........
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BlittyD, you are going to have to read the Tutorial. HOW CLOSE DO I PLACE MY LIGHTS is there.
Less than 105 watt, CFLs go one to two inches close at all times. They make very little heat.....very little.
 
Roseman said:
OK, let me go over this with you.

You have 6 square feet (2 X 3) of growing space. (way too little for those 1000 watts)


The ideal amount of lumens needed is at least 7000 per Square Foot. 6 Sq Ft needs 6 X 7000 = 42000 lumens at least. 60,000 lumens at Most.

Now if you go with 65 watt CFLs...........
you will get 60 to 70 lumens per watt. Let's say 70 lumens per watt, you need 42,000 lumens, so divide 42,000 by 70 and you need 600 watts of CFLs. Divide that by a 65 watt bulb, you need 9 65 watt bulbs. With ten 65 watt bulbs, you'd be very ample.

Divide them into half 2700 k and half 6500k, and you 'd be perfect. Cost you about $10 to $16 a month to burn them.
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Thank you Roseman. I suppose I will have to decide whether to do 10 65wt CFL or 14 42wt CFL or a combo of the both. Is that correct? I noticed you use different sizes.
 
Roseman, LabRat,Mostly Crazy, Fryingpan, Skooter C: You dudes are sic...Who would think so much info could be learned from the CFL's? Ive been travelin the HPS heavy hitter hiway forever, but the CFL thing has me considering a different route. Good work fellas...:peace: MF
 
I just got back from lowes and all the had was the 65 watt 2700k bulbs for $16. I bought 3. Where should I go to find bulbs on the reverse spectrum?
 
Hey FPF, the notes pretty cool. Were they made in U.S.A.? If you have a Menards in your area, they have the best CFL selection I have seen. They have a large selection of wattage in both spectrums (actually 3 spectrums). Daylight;6500k (veg) bright white;4100k (not really needed,I think) and soft white;2700k (flower) Although a mix of the 6500k and 2700k is best for both phases. :peace:
 
Just tried Home depot and the best they had was the 68 wt CFL bulbs for $15 in the 2700 spectrum. I suppose I will have to order them online. Any input Roseman?
 
420warrior said:
Hey FPF, the notes pretty cool. Were they made in U.S.A.? If you have a Menards in your area, they have the best CFL selection I have seen. They have a large selection of wattage in both spectrums (actually 3 spectrums). Daylight;6500k (veg) bright white;4100k (not really needed,I think) and soft white;2700k (flower) Although a mix of the 6500k and 2700k is best for both phases. :peace:
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PhishyPhil said:
try menards. they had the sprials and the tubes, in all the watts listed above ;)
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It looks like they do not have any Menards on the west coast :straightface:
 
Blitty D said:
Just tried Home depot and the best they had was the 68 wt CFL bulbs for $15 in the 2700 spectrum. I suppose I will have to order them online. Any input Roseman?
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I am not sure which, but I have bought 2700K and 6500K at Lowes and, or Home Depot. Seems the 2700K were in a different section. If you can not find a 65 watt 2700 K locally, either order off the internet or go with more 42 watt, 2700K. I am positive Loses has both kelvins in 42 watt.
 
Lowes, Home Depot, and Menards all have web sites that you can order from. Menards is a little harder to find your way around but is my preference. You can also check your local stores inventory at all 3 sites, if you don't want to take a chance on making a trip for nothing. :peace:
 
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