Nutrition in plants grown under lights vs sunlight

[James Keller]

I've got a friend who has a growing business making blended green drinks and selling them to health food junkies, hippies, people on cleanses, etc.  The drinks are mainly based on romaine lettuce.  Since my system runs cold water for my trout, I am mostly growing leafy greens and lots of romaine.  So I decided to offer to sell her some of my romaine this winter to put in her drinks.  She likes the idea, but the one question she raised is whether the lettuce grown under lights are less energy/nutrient dense than those that she currently gets from traditional farms grown in sunlight.  

I've searched the forums here and have not seemed to find anything relating to this issue.  Does anyone have a place to look for research on this issue? 

Thanks!

James

[Roger]

T-5 system I was speaking of:

http://www.wormsway.com/detail.aspx?t=prod&sku=SPG108

$244 includes bulbs

HID system I was speaking of:

http://www.wormsway.com/specials_2011.aspx

$362, not on sale

Just wanted to point out I was suggesting pricing I'm familiar with at the shop I do business with.  They definitely aren't the cheapest, but we've really only got 5 shops in the entire state of Indiana.  I think you brought a lot of good information to the table and enjoyed reading your post.  The only statement I didn't care for was the MJ one.  I don't think you need to have experience growing MJ to work in a hydro shop, at least the ones here in Indiana.  I mean it isn't legal here.  If you have experience growing a variety of plants I believe you can give anyone good advice about growing regardless of what they are growing.

Just saying bro.  Good luck with your workshops next week!

Jon Parr said:

Roger, brother, if you stick your neck out there you gotta expect a swing of the axe, eh? You work in a hydro store, give it to us straight...

8 bulb t-5 fixture is more like $250-300, right? Plus bulbs at $50-75, plus tax an shipping, totals more like $400 than $200. Compare:
http://www.plantlightinghydroponics.com/new-wave-4ft-8lamp-40000-lu... now even though it claims 40k lumens for a 4' x 4' pad, we really know that it covers a 2' x 4', maybe 3' at a stretch. But what the hell, call it 4x4.

Now a 400 watt HPS really costs more like $200, right. Be honest. Here's a whole kit including bulb for $155. http://www.plantlightinghydroponics.com/econowing-400w-hps-crop-mas... So, easily under $200. Even the most overpriced, top of the line product will be less than $400. Now that one shows 50k lumens for a 5' x 5' area. Again, what the hell, call it 4'x 4'.

Same wattage, half the initial investment for HID, and I'll bet my right nut (I can't bet my left, as I just wagered it in another thread a few minutes ago) it will out produce the t-5's by double. Oh, and bulbs outlast t-5s in every way, replacement is $20 for HID, at least $50 for t-5's. Now I like t-5's just fine, but you need to back up your claim. You work in a hydro store and don't have any experience growing MJ? If that's true, you should quit. That's like a vegan working at a steak-house. You've never been asked about the nutritional yield in plants grown with artificial light? That's because hydro clients don't expect nutrition from their crop. I get asked that question all the time, probably because I don't work at a hydro store. You wouldn't recommend a light based on the hydro industry's chief client? Why not, they know their stuff.

I'm really not trying to pick a fight, just trying to keep it real. HID is cheaper and better than flouros, period. Let's not forget that flouros must be used as the only source of light as well, because the fixture blocks the entire area of natural light. HID can be used as supplemental light because of its small footprint. A chrome-dome with remote ballast casts almost no shadow.

Lumens are a measure of light visible to the human eye, and because of the particulars of the eye, lumens stack more points in the greens, and taper off markedly on each side, tallying nothing for UV or infrared. Since plants don't use green, and do use UV and far reds, lumens are a piss poor unit for measuring plant light needs. PAR is much much better, but sometimes hard to find a published rating. How deep light penetrates a canopy is dependent on light "intensity". 50k lumens from a pinky-sized arc tube? Very intense, very deep penetration. 40k lumens from 8 sq ft of t-5 tubes? Very weak, very poor penetration. My beloved CMH bulbs only put out like 35k lumens, as opposed to 50-55k for the same wattage HPS, however I have seen better results from CMH. This is because the lumens rating sucks. I've never looked up PAR rating for the two. I'll do that shortly.

[Carey Ma]

That's right Roger, One does not have to have experience growing MJ to work in a Hydro shop and legally, you should not tell your custies how to grow MJ but you can tell them how to grow tomatoes in winter...;)

My hemp grows great under lights as well! Yes, I grow hemp. My grandpa grew hemp and so did all my ancestors ever since we got land in Indiana, over a hundred and fifty years ago. The word marijuana is a dirty word in my book so you will never hear me use it and I hope less of you will because that word was used by our beloved federal gov that does nothing harmful and only protects it's charges, "accidentally" hoodwinked our forfathers to abandon this fantastic crop in lue of chemical company's new wonder, Rayon. I'm not talking about the class that has a high THC rating (medical) but the mirical plant that sustained our country and sustainable farming with superior fiber, fodder for animals and seeds that are a balanced feed in of itself as well as superior oil that could be derived from them. As you can tell, I am very pro hemp and hope all of you would write to your representatives to reverse this unfair law that has done more to criminalize good and decent people, spending astronomical amounts on a loosing battle that should never have started in the first place.

Oh BTW, I was originally a Hoosier too. My mom lives in Kokomo.

@ Jon and everyone else talking about types of lighting: I thought the question was; "whether the lettuce grown under lights are less energy/nutrient dense than those that she currently gets from traditional farms grown in sunlight." I assumed, this assumes that he already knows how and is using lights so why the long drag out about what type of lights? Aside from that, I agree with you. I have used MH and HPS to grow winter tomatoes for years without significant deperciation in brix levels.

[Jon Parr]

Fair enough, Roger (and thanks for my workshop plug) although the actual price in the 400W HPS you listed as example is $307, not "on sale" but everyday "kit" price, and includes a $72 hyped-up MJ bulb. The standard mag kit above it is $242. So your source of lights here (is that where you work?) puts both packages (T-5 and HPS) at about the same price, watt per watt. Even so, coverage area has to be weighed to compare apples to apples. The HPS is recommended for 5' x 5', or 25 sq ft, the T-5's 4' x 4' and in reality, they only properly light a 2' x 4' area, or 8 sq ft. We could do a comparison grow, which I'm all for. I have an 8 bulb T-5 HO fixture just gathering dust anyway, and a couple of old 400W HPS streetlights, one for HPS and one for CMH. What say you, fellas? I've been dying to get an accurate side-by-side HPS/CMH result anyway. May as well sink the T-5 ship while I'm at it.

Details:

4' x 4' x 4' insulated mylar cubes for each chamber, identical fan configs and ventilation, lettuce starts from same seed tray and growing in floating raft DWC in 3 separate 4' x 4' x 1' deep troughs in parallel from a common FT, powered by 20 small sturgeon. Will measure power draw for each bay with kill-a-watt meters, 12 hrs of light each, and weigh in the results. I think a nutritional analysis is out of my reach, but will keep that in mind. Suggestions/mods? Jeesh, 1200 watts plus ballasts and fans, 1400 watts at 12 hours at $.40 per KWH, that's like $200 per month for 216 heads of lettuce. And you people pretend hydro shops are for growing lettuce......BTW, Roger, I should not have implied that you were not qualified to work at a hydro store, having no experience in MJ. Around here, 90% of hydro store customers grow only weed, and the other 10% grow weed and veggies. I can only assume Indiana (legal or not) is the same, but perhaps more discrete. I am not, however, from Indiana. 

@Carey Ma, I sure appreciate your input. And I agree that making hemp illegal was a great loss for the american people. It really is a super-plant, with respects fiber, nutrition, oil, and medicine. And to think the goody two-shoes of the time were duped for the sake of polyester. Why all the lighting discussion on this thread? I suppose because I think the general population, including those on this forum, think that flouros are cheaper, better, more efficient, and safer for the environment. I strongly disagree on all accounts. And the OP was concerned with nutritional quality of plants grown under artificial light, but did not describe the type of artificial light in question. Artificial light can be good, exceeding the intensity of natural sunlight. It can also be bad, and from the article I linked earlier, poor lighting is not just disappointing and no doubt nutritionally inferior, but actually carcinogenic. Most of the pictures of indoor AP gardens on this site are under-lit, and done so with flouros. And the poor suckers are thinking they are saving money.

[Carey Ma]

OK if we're going to talk about lighting then I'll chip my two cents in as well. In my opinion, I think most people can't afford to crank the approprate PAR. Let me explain. PAR is the actual energy bandwidths plants use to transform and grow. This type of lighting has little to do with what we call visible light. Fortunately,the way anybulb produces light does so in spikes. Some of these spikes coinside with what plants can use. But to get a full spectrum, one has to bump the low or weak spots into the useful capacity, so, have to increase the output tremendously.

Todays high output floro does a wonderful job: less heat output at a lower wattage. They are great if you can get them right-close to the plants. So small area of true effect, and this would be limited to small shrot plants, however, they are missing alot of .bandwidths necessary for propper growth. I use T-5s over my sprouting trays but use 1,000 Wt MH or HPS for my winter tobacco and tomatoes and anything else that fruits and is worth growing. Expensive? Yes! Hell Yes! But I'm worth every penny of it. I'd rather spend nine bucks for a pound of my heirloom tomato than buy an ounce of Godiva's chocolate. This year, I have done extensive experiments with Pee-ponics with wonderful results. I hope to continue these tomatoes through the winter or as long as they continue to produce. If I'm lucky,I might turn them into tomato trees like we did in the Shangdong Ag Fair a few years ago.

I've experimented with wattage and source and have come to the conclusion that there can never be enough light, just too much heat. One way to do that using HID lightingis the use of "Smartglass", inconjunction with water or air cooling/ ventilation. If one can afford it,I thoink "Smartglass" would be wonderful on a greenhouse, esp.in extreme environments.

OK, back to Indiana. Indiana is one state you don't want to be busted for pot/ MJ. Seven years hard time for one joint. You can buy full auto machineguns and you can blast or blow up anything you want but get busted with a spleef. Your done for. Extremely hot andmuggy with fat rain inthe summer and bitter cold in winter. Washington State on the other hand is far different in all respects. Thank you software industry voters.

Well thats my babble for today.

Cheers all.

[Vlad Jovanovic]

Right Carey. This is why florescent tubes do such a bad job (comparatively speaking) at growing plants, especially if used for more than 5-7 months. Single phosphor coated florescent lights get most of their lumens from a very narrow 'bandwith'...Great for human eyes, crappy for growing plants. The exception to this are tri-phosphor coated floros (this in part is why I like my PL-lights, they are tri-phosphor standard).

PAR and CRI (color rating index) have somewhat of a correlation going, and since most manufacturers do not list, nor examine, PAR emitted by their lights (LED manufacturers being the exception), but do list CRI we must use CRI as a 'rough' indication of PAR.

Florescent lights have pretty low CRI ratings, even the "daylight tubes" are rated at about 76, "cool white's" about 62 and "warm white" at about 55. Anything below 80 kinda sucks. 

Jons CMH bulbs have a CRI of 96...which is phenomenal...My MH bulbs are rated at 85 which is 'good'...If we were to visualize the CRI rating of a floro as a graph it would look like an isosceles triangle with the apex in the 'green wavelength' region. To the extreme left and right corners of the triangle would be the 'red' and 'blue' "PAR-ish" regions. As time (months) passes the 'triangle' shrinks a bit, pulling away from the left and from the right but still centered heavily in the 'green'...what little lumens coming from PAR there was, all but disappears. 

CRI is not to be confused with their Kelvin temperature, nor lumens. CRI is a measurement of a light source's accuracy in rendering different colors when compared to a reference light source with the same correlated color temperature (in Kelvins). It generally ranges from 0 for a source like a low-pressure sodium vapor lamp, which is monochromatic, to 100, for a source like an incandescent light bulb, which emits essentially blackbody radiation. The higher the CRI, the better the visual perception of colors. Again, although this index is basically for 'human eyes', but there is a correlation to PAR since more light from a broader range of the spectrum (three or four peak wavelengths instead of just one) is being produced with a higher CRI.

This is why I believe Jon stated that Watt for Watt you are getting much more plant usable light with an HID versus a floro tube. Not only are you getting vastly more lumens, but more plant usable lumens with HID's (particularly CMH bulbs)...

 

[Jon Parr]

CMH offer still stands. It's sitting on the shelf with VLAD written in sharpie.

[mattyG]

Hi!

After reading through this I'm convinced that a CMH bulb is what I need! Could anybody suggest a good place to get a kit/bulb for this?

I've got a small indoor setup sitting in front of a window with a large bell pepper plant that I brought inside when it got cold and recently planted lettuce and cilantro. The pepper just started to blossom again but the lettuce is stretching pretty bad, so I think I need a grow light.

Would appreciate any suggestions!

[Jon Parr]

http://www.advancedtechlighting.com/cdmed18.htm

[Vlad Jovanovic]

Hey Jon, did you ever get my message about your CMH offer? I know that you had said that you'd mail them free of charge and all, but I'd like to trade you 4 songs that I wrote and recorded for your bulbs. (I'm sure that I'm coming out on the good end of the deal, but that's all I've got :)

[Jon Parr]

Indeed I did, Vlad. I was out of town for a bit, but I mailed it last week, 3 day delivery plus customs on your end. You should have it any day.

And hell yes I'll trade for some music, can you send it as an audio file? I can't wait.

[e-mail]