View Full Version : CFL lumen help pls!
casual
09-01-2009, 08:36 PM
so, i was strolling around the forum, i found 2000 lumens sq. ft./21500 lumens sq. m. = Absolute minimum for growth. You won't get much from this, especially after the plant has grown a bit. Not really enough to flower well.
3000 lumens sq. ft./32250 lumens sq. m. = Pretty Good growth. Enough light for the entire light cycle, although your yields may be lower.
4000 lumens sq. ft./43000 lumens sq. m. = Very good growth. Once you pass around 3500, growth rate and ability goes up fast.
Over 5000 lumens sq. ft./53750 lumens sq. m. = Optimal growth. Dense growth in all stages.
So, in the "potential" setup that i have going, i have 17200 Lumen's going onto one plant. Will this be enough for my baby? She will be 3ft tall at the end of her life i suspect. Does that mean i need 15k lumens to be well off with her? or can i take down some lightsand save some energy? Also my lamps are 6-4 inches away from leaves, the maxium lumen absorbtion.
It just seems to me that she's not growing fast enough. a month in and we're at 1 foot. i don't think its the soil, or the nutes. It gets plenty of fresh air, constant air flow round it. just wondering if it could be the lights, i dont know where to look after that. Half are 2700k spectrum, other half are 6500k.
casual
09-01-2009, 08:42 PM
Posting pics soon waiting for battery to charge.. she looks healthy (reason i say she cause she just popped out her pistils) just wondering what everyone has to say, wether the leaves are to small, and what the growth at the top of the plant is, cause i never topped her, she climbed and climbed then stopped there for about 5 days now. I dont know what it is. you'll see soon. Ty
casual
09-01-2009, 09:27 PM
so these are the pics, pic 1 is the whole plant in view, pic 2 is the other side, and pic 3 is the top i was talking about. It just stopped growing up. and has a ballish shape of growth. zoom in, tell me what you see. Ty
headshake
09-01-2009, 11:00 PM
most people consider 5000 lumens/sq ft MINIMUM for a worthwhile harvest. it can be done with less, but it's really not worth it.
so what is the area of your grow space/cab? this is important in figuring out if your light is sufficient.
CFLs should be kept within ~1-4" from your canopy top.
i usually veg eight or so plants under 6 x 23W, 1700 lumen, 6500K CFLs and it seems like my plants are bigger than than that at one month.
i've got a batch that i've just started. although it won't help you know i will share in the future for a difinitve answer.
have you checked your roots lately to make sure that they aren't getting snug in that pot?
-shake
Roughrider
09-02-2009, 12:56 AM
I'd say your plants are fairly healthy, although I agree with headshake...you probably need to transplant.
5000 lumens per sq. ft. is for flat surface area, not volume. So if you've got 17,000 lumens, you've got enough light to give a plant that is 3.4 sq. ft.--about a 22" x 22" space. That's enough a very good sized plant.
The problem with CFLs is that they aren't as good for bigger plants, since they don't have good canopy penetration. One thing you might want to consider is having about 3/4 of your lights on top, and 1/4 of them along the sides to promote budding. If, for instance, your plant is more like 18" x 18" (and I've had some 30-36" plants that were about that size), you can have 12,000 lumens on top, and 5,000 on the sides. That supplemental light under the canopy will help a lot.
casual
09-02-2009, 05:10 PM
Thanks for all the posts guys! i love to get help from the cannabis community. To answer your question, my lights are all provided by CFL's which are held in place by Lamps.Therefore, im sure you can imagine that my plant gets plenty of light. She gets a lamp 360 degree's around, and two on top. It's great to see now how it glows light green. I also moved the light's closer. I checked on her eariler today. I will take more pics tomorrow before the lights go off. She looks better, but she is not ready for a transplant yet. She needs 1 more week according to my calculations. She's only been in this pot for about 2 weeks. To me, this isn't enough time for it tobecome rootbound and to diminish the most stress possible from transplanting. Also the top center "ball" has developed into a bud spot very clearly. Today, the spot is engulfed with pistils and small leaves growing. HOORAY!
I almost forgot, i never mentioned temps.They are extremely stable thanks to my basement, 74 degrees lights on, 72 lights off. CFL's prodce little heat, it makes venting easy.
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