Been doing a lot of reading and I am planning on doing a CFL only closet grow. I am still researching, but the grow chambers will be 6 sq' each (1 veg, 1 flower) and probably hydro. SO what I am wondering is within 6 sq' with CFL's (particularly for the flowering cycle, I am thinking ScroG, as my vertical space is limited (3'), maybe 3 plants to flower at a time? And.. If I use inexpensive 23 watt (actual) 1600 lumen Philips Energy Saver Twisters (colour temps are 3100,4500,5000,6500) and considering the proximity that I can place the CFL's to the plants what mix/qty's of the bulbs should I be considering? Unfortunately the datasheets for these lights do not include a spectrum chart, which sux. Googling seems to indicate that the 6500K (daylight) has a robust output in everything below 600nm, so lots of blue/green/white, but for flowering my concern is that even the lower temp bulbs are still not going to have sufficient 600nm+ output. What should the peak spectrals be at for veg and flower? NOTE: I am also looking at using high output energy advantage T5 (tube type) lights, but I haven't priced them out yet. These lights DO provide the photo-metrics and I noticed that even though they are rated at (3000, 3500, 4100, 5000K) for colour temps, the 3000K (warm white) 49 watt 5000 lumen spends about 60% of its light energy in the 550 and 650 nanometre peaks. Is that enough "red"? The 550nm green/yellow is probably just a waste of energy I am guessing? Temperature control and power consumption prevent me from considering HPS lights. I am wondering how I can supplement the 600nm+ range for flowering. Would be nice if there was a calculation for watts/Lumens/plants, but everything i have see so far calls for crazy high Lumens which are calculations that I doubt work for CFL's.
T5's and CFL's work just fine in my opinion. My results are just the same or better than a friend of mine that is using a 400 watt HPS. On a 8 to 10 sq. ft. grow I'm currently running. ( flowering section only ) 2 x 65 watt CFL's, 6700K - 7,600 lumens. 1 x 68 watt CFL, 2700K - 4,200 lumens. 2 x 58 watt 4ft. T-5's, 2700K - 10,000 lumens Total lumens 21,800 Lumens per. sq. ft. 2,180 - 2,725 ( depending on # of plants ) 10 max. This is working for me with 6 plants right now, and I am sure I could easily push that to 8 or 10. Home Depot has the CFL's priced at around $14 ea. And anything in the 2700k to 3000k range will work just fine for flowering. Hope that helps you.
Fantastic info, really appreciate it. I presume you are using some of the light at different orientations to the plants, rather than all overhead? I would also be interested to know what brand/models the lights are. If you have the time. I am still trying to figure out what kind of reflectors I should use as well. The HomeDepot and Rona closest to me have a crap selection of lighting fixtures so it looks like I am going DIY.
What I am using is a 65 watt CFL shop light made by a company called Designers Edge. Model # L- 81 And it came with the 2 - 6700K daylight bulbs. The local hardware store I bought it at had them for $54 including bulbs. It and the GrowBright HO 4 ft. 2 bulb T5 fixture hang overhead. And the T5 fixture I purchased for $99.95 from HTG Supply. Fluorescent Grow Lights The other 68 watt CFL which is 2700K I bought at Home Depot for $14. ( brand name is TCP ) I use a $12 clamp on light with ceramic socket and aluminum reflector for it, and I use this for side lighting. I have so much reflective mylar insulation in my room that I don't really see any need for more side lighting. Besides the fact that in the past when I have given plants a lot of side lighting. I never really noticed that big of a difference. For me this combination seems to work. There are so many factors which can change what works for one person and doesn't for another. Region and climate., strain or strains to be grown, size of room, ventilation .insulation, and of course wether you are growing for light or heavy personal use or even more. Here is a link to some pics of my little grow. Can I use T5's and get proper results? - Grasscity.com Forums I didn't add the pictures of the veg. section yet as I am still working on that.... But it is on the right hand side of the second picture. Behind the mylar insulation. Which is held in place by velcro.
Ghetto DVD spectroscope of my CFL's As we can see, lots of wasted light energy in certain ranges. Better digital camera would help, but to the eye you can actually see very detailed info including specific gaps in wavelength ranges. I was a bit surprised at how much green is going on with a 2700K CFL. In any event, NOW I can test any light source I may wish to use for spectral relevance.
Glad you took the time to do a little research. The Lumens mentioned on a CFL's box are the max visible light that we will see. The amount of lumens that a plant is able to use various depending on the nm. Look below - The left side of the table is the SPD (Spectral Power Distribution). The colored section is the "par" for plants... their ideal levels of light intensity based on the spectrum. The red line is a 600w HPS. The white line is irrelevant. The left side of the table is the SPD (Spectral Power Distribution). The colored section is the "par" for plants... their ideal levels of light intensity based on the spectrum. The orange line is the sun. The best suggestion I can give is to use wattage. Make sure you use the true wattage (not the "compared to"). 100 watts for the first plant + 50 watts for each additional. You should use both extremes color temp extremes.. as you have.. 6500k for veg, and 2500k for flower. You can also supplement with LED's.
Yes, I've done a considerable amount of research since the OP. Thanks for the images, I have also found these in my travels. Sun versus CFL (of some unknown make/model) NOW, here is an interesting one, as it clearly indicates that the Violet/Blue spectrum is better for photosynthetic action, BUT that seems contrary to some other data, particularly the NASA LED grow light experiment which says that the red spectrum is better utilized (paraphrasing, cant find the link right now). The NASA data is why we see LED grow panels that are primarily red with a bit of blue and orange thrown in. Also notably is that some individuals who have used the T5 HO lights during veg have created too much UV and caused plants to flower prematurely, even in 18/6 cycles. So there definitely seems to be some contradictory data out there on what spectrums to use and when. Of course plant genetics plays a part in this as well, but that would really only be used in a case of dialing-in one specific strain. The reason I have been looking into the SPD of the CFL's is simply power efficiency in relationship to the plants photosynthetic processes. There is a really good T5 HO (aquarium coral tube) thread that delves into this in detail, alas it's in another forum so I leave it to you to explore google. Perhaps we can glean some of that info for this thread. I have also been looking into filters and coloured lighting although this would remove unused wavelength ranges, it doesn't save any power. One thing to note, there are people out there that will flame you or try to high-jack threads as soon as you bring science into the whole lighting issue, weird I know. I haven't seen that in this forum though. I guess some people just get "trolly" when they are stoned, lmao. Notably people fixate on CFL colour temperature ratings which are (more or less) meaningless IMHO. At best those colour temperature ratings 2700K/6500K etc and their associated verbiage, cool white, soft white; should only be used as a very general guideline to the types of outputs they create and even then, the spectral out puts across different manufacturers with the same descriptors will vary considerably in some cases. Right now I am using 92 actual CFL watts for one plant in a compact tote grow. I am thinking of adding some UV blacklights into that scenario at flower. The LED and T5 buy-in right now is outside my available funding. In any event I will be scrutinizing my light sources much more in the future and tailoring the spectrum as much as I can.
Yeah, plants can unitize a lot more light in the 600-750 nm range. That would agree with NASA's research. If you are going for the best spectrum, then CFL's really aren't a great choice lol. But I don't think it's even debatable that they are best light style for the price. For Veg, I use four 90w led UFO's in purple, 40w magenta Kessil, and 104w 6500k CFL grow lights. When I switched to flower, I removed all the CFL's and put in a 250w HPS. My grow is full spectrum with heavy emphasis on the orange and reds during flowering. If you can keep your room cool, you may want to look into 150w HPS lights with a built in ballast. If you have more money, you could use a bloom booster. My Magenta Kessil is my supplemental bloom booster but they are extremely expensive. It seems like you have a good idea of what you're talking about. I doubt you'll have very many problems figuring out your lighting situation.
Thanks. Love that Kessil, why did you go with the Magenta and not the red? Just curious. (I guess they are virtually the same but you get that little bump in the 400-500nm range) Of course my first thought it how can I replicate that on the cheap, heh heh, but the good high lumen/watt LED's (the actual LED's themselves, not a already manufactured lights) are REALLY expensive, so you can DIY if you have the soldering skills, but I need to find some cheaper LED sources. Thats the direction I see myself heading in the future. Thanks for the data on the Kessil, I hadn't heard of them.