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Mar 10, 2013 9:10 PM CST
|I'm thinking of extending the growing season for some of my seedlings this year that I started a bit late, but have never used lights, indoor growing methods, or even anything more technologically advanced than a polytunnel to keep off excessive winter rain and spring frosts. We really don't get severe winter weather here, but we get short days!|
So I'm asking... any of you guys that have experience, what kinds of lights do you use? I have to keep power consumption to an absolute minimum. What kind of set up?
I've just scored an old double-glazed door refrigeration unit that I'd like to lie on its back outdoors. I guess that would kind of make it an insulated cold-frame right now, but if I were to add lighting, what are the options? Any kind of minimum heating required too? I wonder what effect frost on the outside of the unit would have....
I know there's been alot of mention of lights in other threads, but being as scattered as I am, it would help me to have any hints/advice here in one thread.
Mar 11, 2013 6:33 AM CST
|I think Anthony is the one who is best suited to give you the best advise on how to handle this scenario, considering your seasonal weather averages and all. Given your moderate climate, I'm sort of puzzeled why you you would need to go through the extra work of adding lights; but it it certainly won't hurt and of course, it will help produce bigger baby bulbs. The question will become, how long are you going to extend the growing? I'd say if you have two true leaves you would be ok just letting them go dormant as they are.|
I had a late group here last Fall. I brought them inside and grew them out an additional 3 months before I began to force dormancy. Refer to my posts in the 'Starting Lilies From Seed' thread: Nov 4th, Nov 29th, Jan 1st, Jan 27th, for a little background on what I did. I used the same light setup that I use for starting my seedlings: a Hydrofarm 'Jumpstart' unit that has a single T5 type 48' AgriGro 6500k, 5000 lumin, 54 watt bulb. The bulb height was adjust to about 12 to 15 inches above the plants and run for 16 hours on, 8 hours off. This single bulb setup will accomodate 12 six inch 1 gallon pots when they are in 2 rows of six and probably is all you would need. But since I had extra setup (units) from seeding, I eventually added two more in my theory of packing in as much growth as I could in the shortest possible time frame. It worked great. Although--I do think I was providing way more light than necessary with the extra units-?- For smaller applications, there is a 24 inch type T5, 26 watt model available which gives off the same light wavelengths as the larger one. I prefer the AgriGro T5 lights because they are cool and seem to give off the right spectrum of light that lilies like. There are other bulb types out there too, like T8 setups one can do, with a variety of k and lumin values and with a variety of wavelenght/spectrum profiles but this is the one I settled down with for lilies I'll edit in some photos when I pull out a box.
Edit in Photos added:
In the last photo, those are 1 gallon, 6 and 1/2 inch diameter pots of clones that I just pulled from the the cold room (rooting), but it illustrates how many pots will fit with a 48' setup. The light itself is easily adjusted up or down for height.
Mar 11, 2013 7:16 AM CST
|T12 florescent tubes are more energy efficient than incandescent (regular bulbs)|
T8 more efficient than T12
T5 more efficient than T8
T12s are being phased out in the USA.
certain T8s will be phased starting in July in the USA.
6500K is the best temperature for plants. If you can't find them, get the closest you can find, most likely a lower temperature K.
The lower you go, the less light usable by plants is produced.
High output 4ft T5 6500K (54W) is what I am transitioning to.
4ft models are slightly more energy efficient than twice as many of the 2ft models.
It might be a concern that the heat from the ballasts and lights will be too much in an insulated box. (or it may be a benefit.) You will have to monitor the temps.
I am not sure if Lorn's "12-15 inches above the plant" is actually above the plant or above the table that the pot and plant sits on. 12-15" above the plant itself seems to me to be quite a long way. Lumens lost per inch of distance is hugely substantial with florescent tubes. When I used cool white T12s, my tomatoes and peppers would grow up into the light fixture and sometimes leaves actually touched the tubes. They loved it. With 6500K, I would aim for the closest plant leaves to be at about 4 inches away, if possible. In a more practical sense, you probably be farther. LED technology for plants hasn't advanced enough yet to use for plants, IMO.
Mar 11, 2013 8:26 AM CST
|Well, let's see. Those were 6 inch high pots Soil level about 1 inch less than pot height, plants were about 2 to 4 inches high. So, I was running about an effective height of 7 to 10 inches above soil level or so throughout. I guess the main thing is to have it as close as reasonable without damaging the leaves. I raised mine once during the process when I saw some yellowing and browning on a couple of the taller leaf tips. I suppose in the beginning, one could start out a little on the high side and work down to that point and then move the height back up perodically as the plants grow. Kind of trial and error; main thing is watch for leaf damage. Keep in mind I was running two and three units also--but I think one would do just fine with a single unit at a lower height as Rick suggests.|
Mar 11, 2013 7:37 PM CST
Roosterlorn said:.. So, I was running about an effective height of 7 to 10 inches above soil level or so throughout.
Certainly within good parameters, especially when using multiple florescent tubes. Really, it's not rocket science (although pot growers will disagree ), just being in the ball park is adequate. Nature's light intensity can vary hugely, even from day to day (sunny or overcast). But as a constant, if florescent lights were 12-15 inches above the leaves, IMO, that's not in the ballpark of good growth for lilies, even though they will grow.
I just didn't want anyone to get the wrong idea. It's like when people say how deep they plant their bulbs: is the depth they are quoting from the top of the bulb to the surface, or the recommended definition: from the base of the bulb to the soil surface. Right or wrong, my definition of "above the plants" is above the plants, not above the base of the pot that the plant grows in. So I am glad I asked.
Mar 12, 2013 6:47 AM CST
|Della, as to how you could mount light fixtures in your horizontal refridge would be quite easy. Most all light fixtures like this come with hooks and chains for adjusting height so all you'd need to do is screw anchors in on each side (or top and bottom) and suspend it from there. You can adjust your height by raising or lowering the hooks on your chain. In the case of the grow light I showed yesterday you would simply remove and use only the light fixture. But there are other cheaper options set up wise, too, although they aren't quite as efficient. Here's another set up I use utilizing double T8's, 3000 lumins each, 32 watts each or a total of 6000 lumins at 64 watts: |
: shop like fixture (less than $20.00 US)
: note double dome reflector
: Sylvania Gro Lux bulbs (about $8.00 each, US
: slots for hooks (usually included)
Other items you'll need would be a timer and thermometer, of course. If this were not a metal enclosure, an RF remote thermometer would have been great.
But, like I say, usually I put my seedlings in the greenhouse in the fall when we get a few light frosts. They get an extra 2 or 3 or maybe sometimes 4 weeks growing in there and then they eventually go dormant or freeze off in there. The only other time I got into a circumstance of very late growing was last fall with some late germinaters that I grew throughout the winter inside, have now been forced dormant and are currently in cold storage (I'll update in another thread)
Mar 12, 2013 8:16 PM CST
|Just want to make sure that everyone understands that the 6000 lumins at 64 watts (in the post above) doesn't mean it's brighter in total or more powerful than a single 5000 lumin unit; it's not! It is still only 3000 lumins/bulb--or 60% as bright, but it would give a wider area of coverage, that's all. Still ok tho.|
Mar 12, 2013 9:35 PM CST
| <--- me, going... oh wow, it may not be rocket science but my brain has an electronics-shaped blind spot. And I've only just realised that 'K' is not a measure of lumens, but something else entirely. Now the science of which part of spectrum etc.... my mind starts to boggle :D|
To be honest, I'm not sure if I need to use lights, but I'm concerned for some of my babies. The warmest summer we've had in ages lulled me into, well... planting some seed later than I would normally. So I have just cotyledons right now, and more hairpins coming through. They're really valuable to me, and I want them to get big before winter. Though yesterday was a scorcher again, nights have already been dropping enough to give me a bit of a 'brrrr' response in the mornings, and other plants are giving strong indications of finishing growth early this year. (Mixed signals maybe have them confused, but being dry also probably hastens/heightens the biological shut down process?)
Anyways - very good to know that two true leaves should see them through the winter. Of course I'm impatient too, and would love them to flower sooner rather than later, so the more growth now the better (I hope!).
Just had a chance for a brief look at some of the tubes. Seems T5s are sold here as aquarium lights. I came across alot of LEDs being marketed to hydroponic (aka pot) growers, and they look to use much less power along with generating less heat - maybe good for an insulated chamber? Rick, could you elaborate on why you think LEDs aren't up to scratch yet? They kind of look like christmas lights...so many different colours being sold with various advantages attached to their bit of the spectrum. I'm not at all interested in inducing anything to flower (unlike the pot growers :D)... and I'm getting myself confused as to the best bits of the spectrum, and how this relates to best Kelvin measure and lumen. I get myself in these messes!
It will take me time to really absorb the info you've both shared.
I was wondering if I could get away with fitting a long tube to the existing wiring, though it sounds simple enough to attach something else. Just took a couple of pictures of the unit:
Apologies - I must seem really garbled. I'm rushed, distracted and haven't had time for adequate comprehension. In a less fraught moment I'll be able to make some progress. Thanks so much for your help.
Mar 13, 2013 5:44 AM CST
|Della, not all T5's or T8's are the same spectrum wise. Make sure you get Hydrofarm HydoGrow or Sylvania Grow-Lux or equilivent. Some upscale garden centers should have them; if not they can order them. Same for any big box store or good local hardware store. Or you can order them on the internet. If you go with the 48 inch tubes, you'll need about 50 inches overall; somewhere in the nieghborhood of 128-132 cm I suppose--do you have that? Oh, keep in mind to get a light fixture with a good reflecter backing ( see pics below), You'll want to get the most out of your lights. Note also the little 'S' hooks and chain setup for hanging/mounting--but you can get innovative there also.|
As far as LED lights--Rick, are they even appropiate for our use with lilies? I certainly don't know enough about them yet--doubt if anybody does. For me anyway, it's a no brainer--I've got too many T5's and T8's around here to even consider a change and the problem is (a nice problem), they all work so well for me that I wouldn't want to change. But, if you're a person starting out new with lights--then it might be a different story.
Here's an 'off the wall' thought, Della--did you ever think of adding mirror tile at a 45' angle to the bottom outer edges? I can invision a reflective system that would give you good lighting at a full 180 degrees. Rick--would this be ok, or do you think it might distort the wavelengh we're after? Just a thought.
Mar 13, 2013 10:15 PM CST
|Do you really need lights? In general, no. Of course it does depend on the natural light you receive at the season in question. If you live in Seattle (Washington), for instance, where winters are very cloudy and rainy, than certainly, you need supplemental artificial light. But anytime, anywhere, more light than what can be naturally received anywhere inside a house will produce faster growing plants.|
Regarding LED lights, the cost will come down drastically in a few years. When CFLs (compact florescent lights) hit the mass market, well after they were first available, Home Depot sold them for $13 for a pack of four. Now, 4-5 years later, they sell for $3. The same (and probably even more drastic) price reduction will occur with LEDs. On top of that, technology is constantly advancing and cheaper will likely also be better quality. When I think back at how many of those first CFLs were returned to the Home Depot where I work compared to now, the difference is staggering. At this time, LEDs for plants all consist of arrays of a multitude of LED lights. For whatever reason (maybe just poor quality?), people have been experiencing individual LEDs "burning out". (They are likely not actually burning out, but are for whatever reason not working.) Most of the time, these LEDs are not individually replaceable, and you need to replace a whole bank of LEDs. As we all know, right now the initial investment of buying an LED light is huge in comparison to florescent (or incandescent) lighting. It's something each person will need to evaluate for himself, but in my opinion, considering both the future reduction in price and rapid advancement in technology, the economics of it has not met a balancing point. I really don't know anything about how visible colors are produced by LEDs. If it is just the light covering that is filtering out certain light wavelengths (as with incandescent bulbs), then the technology has little, if any, advantage for plants. If the light emitted from the diode itself is "colored", then a significant advantage could be there.
If by "existing wiring" you mean the refrigerator, that's not a good idea. Run an independent wiring circuit.
T5's or T8's are the same spectrum wise
If I may elaborate, T5s and T8s can be had in a variety of spectrums(spectra?), but in this respect, it makes no difference which type of florescent tube it is.
Are LEDs even appropriate for lilies?
If they work for other "normal" plants, I can't imagine it would be any different for lilies. There is no difference in how light is used by lilies compare to other plants in general
(including marijuana ). That the emerging market is seemingly dominated by pot grower is not surprising to me. They'll do anything if they think it will get them "higher".
They are, after all, stoned.
Lorn, your "off the wall" thought is not that at all. And I hate to burst your bubble, but you're not the first to think of it, although you deserve kudos that you did. Using mirrors, tin foil or even a white board as you describe, or just as sides to somewhat encloses the "chamber" and reflect light back is very beneficial. For plants growing at the edges of the lighted area, you should observe less leaning in toward the main light source. Yes, the spectrum of light reflected is always different from the spectrum of the light source, but never detrimental to my knowledge.
The idea you present of two 3000 lumen florescent tubes being not as bright as one 5000 lumen tube is correct. Let me build on this concept, because it is important to emphasize that "60% as bright" is only true if the two 3000 lumen tubes are working independently. When working in tandem, as they would be in a double tube fixture, any surface in view of both tubes receives light from both tubes. This doesn't translate arithmetically, in other words, any surface does not receive twice the amount of light as it would from single tube, but it is significant. For a double tube fixture, my guess is that the reduction amounts to something closer to 80%, and still with a wider area of coverage.
Think of two imaginary car headlights pointing at you. They are bright. Now imagine how much brighter they seem as the two headlights move closer together (a two bulb fixture), and how much brighter still they are as they merge into one single source of light. Not a perfect analogy, but I think you'll get the idea.
Well now, if you eyes haven't glazed over yet, you're at least ready for bed....
Mar 14, 2013 6:48 AM CST
|Della--when Rick says: "Do you really need lights?" (or even this set up for that matter?). A set up/project such as yours would work just fime for an unheated garage or shed or under a roof, etc. but out in open air---???. For one thing with an enclosure such as this, you'd be losing all your defussed natural side light and you have to consider too, that any light fixture you put in there is going to create a shadow blocking natural light from above. Something to think about.|
When I look at climate data for Hobart, I see that your average high and low temperature for today is 67'F and 51F. By June 1st, that will drop to 55'F and 40F. Seems to me, these are ideal temperatures for bulb and root growth with the understanding tho, that you have progressively decreasing light values during the period. But like I say, if I have at least two good leaves, then I know I pretty much 'got it made'.
In the meantime, continue to work on getting your project together and have it ready ' to go' so that at some point you decide that your natural outdoor light values have deminished to an extent where you feel you have more to gain by artificial light, then make the switch and continue to grow them out a little more that way.
It's interesting to note that You and Anthony are at 42.8 ' L in the southern hemisphere, while Tracey and I are at 42.6L in the northern. The amount daylights are exactly the opposite for each day of the year. Today you will lose 2 minutes, 57 seconds but we will gain 2 minutes, 55 seconds, or about only 2 or 3 seconds of opposite difference each day. Rick, in Minneapolis will gain 3 minute and 9 seconds of daylight, being just a little further north. Just thought I'd throw that in there.
Mar 14, 2013 9:45 AM CST
|The diffused natural side light is lacking in the refrigerator box because of the sidewalls that don't allow the natural light to enter from the sides. My Grandmother had an open-topped wooden box around her rhubarb during harvest time, to force the leaves to stretch toward the sun and produce longer edible leaf stems. The stems elongated because of the relative lack of light within the dark colored open box. But the fact that the walls of the refrigerator are white will help considerably with reflected light (mentioned earlier) that comes from above. It will be important to clean the inside surfaces very well so they reflect light as much as possible, rather than absorb light.|
Regarding a shadow of natural sunlight caused by the light fixture itself, it would be significant when the refrigerator is situated outside. Unlike any other scenario I can think of, if I had a choice, I would choose a fixture with a small reflector shield in this case, to reduce shadowing. Sunlight is far better and stronger than any artificial light available for us, and the less shadow the better. However, if I had a choice between using a large reflector fixture I already had or buying a new one with a small reflector, I think I'd stay with the one I already own.
I am not understanding, either, why the refrigerator set up would work better in the garage or unheated shed, rather than in the open air. Perhaps Lorn can elaborate.
Mar 14, 2013 12:22 PM CST
|Sure. Ease of access and management; electrical hookups and inside, away from outside weather, rain, etc. lighting units are not usually designed for outdoor use without some protection or cover. And considering the next 4-5 or 6 weeks seems suitable for growing, the seedlings would be best left alone outside until such point the days get so short and the sun becomes so low of an angle that it would, at that point become more advantagous to grow them under lights under cover. But if performed outside, I'm afraid that closing the lid to protect it from rain or frost would result in the unit becoming somewhat a humidity chamber with very little or no air movement--similar to a situation I experience every fall in my little greenhouse here. Keep in mind that high humidity and little air movement is condusive to botrytis--and fungicides, especially copper base, are not effective at temperatures below 50'F. Also, in such a small space if closed and depending on how many seedlings there are, CO2 levels may become too low and limit growth. |
I guess we're all intrigued by Della's new idea--and we love contemplating its best application.
Here's a picture of Hobart from the air. Rosetta's down there somewhere.
Mar 14, 2013 7:32 PM CST
|Agreed in all aspects, Lorn. |
I was sillily (yes, it's a word) focusing all my attention on lighting.
Mar 14, 2013 8:26 PM CST
|Well, one way or another we'll get this setup growing--oops, I mean going! Della, I agree with you in regards to product availability mostly centered around pet store, etc; but be carefull-- there is a big difference between aquaculture and agriculture when it comes to light applications. some of these T5 and T8 so called grow lights sold in pet and aquarium stores don't have as much 'red' or 'blue' light as those designed specifically for terrestial plants. Most are designed to make pet enclosures and aquariums just look pretty while others may have wavelengths as high as 15000 to 20000 designed for deep water aquatic life. Even more fustrating is the help in many of the stores don't know dippity doo about what's best for what and why. So the next time your out looking, jot down some model numbers of different grow light tubes from Hydro Farm/Hrdro Gro, Sylvania Gro-Lux types, and GE, etc. Then go back home and pull up the pdf's of each for all the specs. Then you'll see that some have different color peaks charactur. Some may have sharp peaks while another may have a more broad peak for red and blue. And since we're dealing with growing greenery, we want lots of blue, preferrably in a nice broad peak form. If we were at the flowering stage, we'd be looking to emphasize the red a little more and so on. Of course, you know this part already I think, but I put it out there for some readers who might not.|
Mar 15, 2013 11:03 AM CST
|Maybe it would be helpfull at this point to explain a little more about fluorescent tube lighting and it's applications at it relates to our subect here. So, I'll start out |
(and Rick, if I say something that's not quite right or should be explained a different way--please correct,etc).
Fluorescent tubes are expressed in terms of 'k', such as 3000k, 5000k, 6500k, etc. The 'k' stand for Kelvin (units) and allows us to measure the wavelength or groups of wavelenghts called 'zones' within a spectrum of wavelenghts and chart them for visual comparison of quantity--often referred to as a color temperature chart. Now, two things here: 'k' values have nothing to do with how strong the bulb is, 6500k is not stronger than 3000k. It is only the wavelength. And the only way to increase the strength is to increase the wattage. And color temperature has nothing to do with 'room temperature' nor how much heat is given off. Color temperature,although derived from kelvin values, is more or less a pshycological expression we use to describe how warm and relaxing the lower wavelenghts are as compared to higher wavelegths being more cold, stark and active. The amount of heat given off by any given tube is determined by wattage and bulb inefficiency but it is not related to color temperature.
So, now then, if we were to draw up a horizontal bar graph or bar chart of a spectrum of say (as an example) a full spectrum tube of 0 to 8000, we might find a fairly even distribution of all of the wavelengths at some volume intensity expressed in terms of lumens (or some numerical value) vertically, and 'k' values straight accross the chart. But, by modifying the phosphors within the tube, certain wavelength groups or zones can also be modified (increased or decreased, more of or less of). Modern biology has determined that plants need and utilize primarily, light wavelengths of two different groups/zones, red with about 3000 or a little less and blue, around the 5000 or a little more. These two groups are the wavelengths best absorbed by chlorophyll in photosynthesis. So then, plant grow light tubes are designed with that in mind and instead of a straight line graph, the line would be greatly elevated in the red and blue zones as compared to the other wavelength groups. Most grow lights still contain a full spectrum of light as well, so they appear as an ordinary but very bright fluorescent light and we are able to see and watch plants grow in a light setting we're accustomed to. In theory, red and blue light (pink light) might be all that's really needed. With artificial lighting we are always working with a constant set kelvin values (k) like 3000 and 6500k. In the world outside, plants experience every possible k value under the sun, literally. And, finally, the sum of all the wavelengths intensities emitted by the tube is expressed as total lumens or peak lumen value
Stay away from incandescent bulbs coated blue or red. All that coating does is filter out the rest of the spectrum and show what appears to be red or blue light.
In general, I've found that young, small seedlings do not require a real intense light setting, but as they grow more, they require more and more light according to size. 5000k is about like midday bright sun in the temperate areas. 6500k (+) is sometimes referred to as super daylight. 3000k is similar to sunrise/sunset light; is sometimes referred to as harvest light or fall light. Some people use 3000k lighting for and during germination as well as during blooming.
Rick, maybe you can add in a little more or restate something to make this a little more understandable..
Mar 16, 2013 2:19 AM CST
This is great information.
So far, I've learned what K values are, and I had no idea previously! It makes sense though now, speaking of colour temperature. More like, well, colour theory I guess, in artistic applications. Hot and cold colours etc.... except that higher values (blue) are 'hot' and lower (red), 'cold'. *runs in circles* (it's ok - makes sense in radiation terms ;) )
Now, I'm going for something like 'super daylight'? Something around the 6000-6500k mark. If that's brighter than midday sun, how do tender little babies handle it? The midday sun here is a killer. We have no ozone :D
And I've learned that the whole 't' thing isn't a measure of anything, but a designation of a type of electrical fitting. The existing fitting in the fridge is t110. Glad to know it's not wise to use them, as the only t110 type bulbs I found were for things like forklifts and diggers :D
Indeed, it's the rapidly fading daylight hours that have me worried! Almost 3 minutes less per day. That adds up. Then if we get early frosts... >>
I like the idea of making the inside as reflective as possible - mirror disco for lilies! - I don't want to stretch the seedlings. What I had in mind was supplementing the natural daylight hours. Aiming for 16 hours? I could set it up with a timer to come on before sunrise, but switch off after the sun has gotten up. Or come on in the afternoon maybe and stretch into the evening?
Don't want it to become a botrytis haven. There is some ventilation; I wondered if I might need more. I also imagined I would have the lid open during the day. Now I'm concerned - that would have fittings exposed to weather, and might be a bad thing. But then if I put it under cover, I'd lose the best natural daylight that is still left and have to have lights on/lid closed for the entire cycle.
I've found this online: http://www.ebay.com.au/itm/T5-...
Maybe I really don't need lights... maybe just sheltering long enough to get seddlings up to two leaves. But as I don't already have stacks invested in a set up, I'm happy to experiment. Even maybe give LEDs a go. Don't know what the spectrum breakdown is for this one though.
Name: Anthony Gloriosoides[ sure!]
Rosetta,Tasmania,Australia (Zone 7b)
idont havemuch-but ihave everything
Mar 16, 2013 3:56 AM CST
|'I've seen the light' .. no seriously, Ive never grown under lights.. I push seed sowing into the depths of Autumn..sometimes with good results, but I have to shift containers'continuously',,.ie- tonight will be 9*, but we've had brilliant rain, so all poly boxes are outside[all 26 of them].........because Im too stiff and sore to bring them back inside,.. ...maybe tomorrow |
lily freaks are not geeks!
Mar 16, 2013 5:48 AM CST
|Della, that light you're looking at on ebay is suitable for kitchen, bathroom or office. It most likely consists of a string of LED's inserted into a T5 tube and designed to be an energy efficient replacement for current T5 fluorescent tubes and fits fixtures with T5 connections. SMD stands for surface mounted device, associated with 'through the hole' terminology, meaning 'inserted into', etc. But this light is not suitable for plants since it's a straight line 6500k. There would be no enhanced red or blue zone with this one. |
In your first sentence, you have the 'hot ' and 'cold' colors reversed. the darker color zones are warmest, the lighter zones are the coolest Think of it this way: If you have incandescent lights with a variac control (a dimmer) you can turn down the lights to where you begin to see more of the yellows, oranges, reds and darker. A darker setting is warm and relaxing. Turn up the lights and you see the brighter, higher, cooler end of the spectrum and we, as people, associate that with lively, busy places; the kitchen, bathroom, office, etc. Color 'wheels' associated with fashion, design and paint industries would be relevant in that case.
But for plants, we want to stick with wavelengths and k values and charts or graphs; things like that.
Think of the color spectrum as a straight horizontal line (rather than a wheel). place black on one end (the left) and assign it a numerical value of zero, or '0'k. Place white on the other end and assign it a numerical value of '10000k' (arbitrary). Now you can begin to envision where the red 3000k and blue 5000k zones are. Those are the colors important to us. If you want too, you could go ahead and place all the colors on a k chart.
Keep in mind that T5 fluorescent tubes require a T5 fixture designed just for them. I can list some I'd recommend if you like. Keep in mind too, that if you go the LED route, the lighting would most likely be just red and blue--you wouldn't be watching your seedings with the same lighting you're accustomed too. LED is an area I'm not very Knowledgable with. Of, if you're worried about 6500k burning your seedings--just raise the lamp a little to decrease the intensity, but that most likely would never happen anyway.
Mar 16, 2013 7:27 PM CST
|I think you have a better understanding of these "basic" terms than I do, Lorn. But to clarify a little more, I'm pretty sure that what you are saying is that this 6500k LED set up is not the same as a 6500k florescent. A 6500k florescent tube produces a lot more in both red and blue wavelengths (more blue than red), and the straight 6500k LED produces no blue or red light.|
dellac said:Now, I'm going for something like 'super daylight'? Something around the 6000-6500k mark. If that's brighter than midday sun, how do tender little babies handle it?
Remember the k rating only refers to wavelength, not intensity (brightness). When Lorn said 5000k is roughly midday sun, he is talking about the wavelengths (the quality of the the light), not the intensity (or quantity). Yes, "super daylight" has more plant usable energy per watt, but I don't think that intensity is necessarily translatable in a linear fashion.
Besides, if the light is on when your babies emerge, they will adapt from the beginning. If the light is "too strong", it's likely they will begin poking up, then seemingly sit stagnant while in actuality the are growing a larger root system that is need to sustain them in higher light. Then they will begin above surface growth again.
In florescent tubes, the T sizing is a measure of tube width. Your t110 fitting, Della, doesn't use the same method of measurement/rating. (If it did, then your T110 would be almost ten times the width of a T12 florescent tube!) I didn't want you to use existing refrigerator wiring because you just don't know how things are all connected originally. For instance, how would you know if were or were not powering something else up in the unit? In addition, with florescents and LEDs, there is always some sort of ballast or transformer that is dedicated to a certain type of bulb. Without knowing the specs for the ballast/transformer and the specs of the bulb, you would never know if it is safe to use them together.
I don't know if it would make a difference if you extend the day with lights, or begin the day earlier. If I had to choose, I think I would begin the day with supplemental lighting. My guess is that there would be less water condensation due to a more moderated night temperature. In an earlier thread, I remember Lorn talked about being sure to cut or extend daylight at the beginning of the cycle or the end, but I don't remember now what or if he had anything more to say when I queried him about it.