Fluorescent lighting, Learning curve~

[nolpenthes]

Rather than start this whole post again I've decided to link the thread. ( Hope that's OK ) I thought some of you could benefit by my research/tomfoolery over the last few days.

Please, offer feedback after reading.

This was a very interesting week of research on fluorescent lighting. The one thing I still have yet to find is an accurate measurement of the average PUR/PAR output rating that your standard T5/HO 65K 'grow' lamp produces. If anyone has this information I would greatly appreciate it. ;D

ocps.proboards.com/index.cgi?board=nepenthes&action=display&thread=4218

Much respect
~nOL

[dvg]

That's a very interesting thread Nolan and definitely makes for some food for thought, with regards to fluorescent lighting for the indoor grower..

When we were looking at LEDs for plant lighting a while back, the current research at the time listed the optimum Chorophyll A absorbtion maxima at 430 nm(blue) and 662 nm(red), with a ratio of 3 reds to 1 blue Led considered to be good for indoor growing.

Of interest was a NASA study that also advised using a few orange and green (for intra-canopy penetration) LEDs interspersed into the majority red/blue array for better plant growth. The orange and green LEDs, even though they comprised a very small percentage of the total array, were deemed more useful to the plants's overall health and growth than an array composed of just the red/blue LEDs alone.

Of course sunlight is still the best, but the science of optimum proportioned, refined light spectrums for plant growth is still being experimented with and improved upon.

dvg

[nolpenthes]

great addition D, your input is always appreciated. LED's are muchos I would love to have the resources at this stage in the game to begin experimenting with them. As it stands the GF and I agree a house is next on the list hahahaha

~much respect
NO L

[mikuláš]

Regarding LEDs, the one manufacturer that I've found who openly advertises his wavelengths is HydroGrowLED (www.hydrogrowled.com). Allegedly many other manufacturers are too far away from the necessary wavelengths to produce good results -- you can read a long discussion about these on a marijuana-growers forum:
www.420magazine.com/forums/grow-supply-product-reviews/88642-led-grow-light-review.html
Price has certainly kept me away from experimenting with them.

With regards to HO T5s, just a word of caution: They produce A LOT of heat (learned that the hard way). I lit an 18" W x 48" L enclosure with just one dual-bulb HO T5 fixture and the coloring on my plants was great -- actually, it seemed a bit much for my Miranda, which makes pitchers that look less washed-out now that it's in shadier spot outside. I used 1 grow bulb (6400K) and one bloom bulb (3000K) with good results -- lots of red-tinted leaves as well.

[mikuláš]

One more link of interest that I found very informative:

www.waynesthisandthat.com/fluorescent.html

[dvg]

Sept 29, 2010 6:41:30 GMT -10 mikuláš said:

One more link of interest that I found very informative:

www.waynesthisandthat.com/fluorescent.html

That's some very good info Mikulas.

Thanks for posting that.

dvg

[nolpenthes]

Thanks for the replies! Much respect

From what I gather, all of the bulbs available on the market today will tell you exactly what color temperature the lamp is, the lumen output and CRI also both being readily available. Just like the above link though these factors having zip zilch zero to do with the bulbs actual effective growing radiation. They only relate to how we visibly SEE the colors enhanced by the light. There are many charts/graphs relaying CRI and the visible color temperature ranges a bulb has, most boasting HUGE spikes in the blues and reds. These charts are relative to nothing, they ONLY show the visible representation of light to our eyes, not the plant. They are trying to sell YOU a bulb, not the plant. The two factors that should really be taken in to account are near impossible to find mention of. I believe it is because they both represent a measurement of radiation, a very taboo term.

The 'PUR' and 'PAR' of any lamp. ( A detailed link explaining what both of these terms are is in my first post ;D )

Even though a bulb will brag a very powerful lumen output or a 65k color temperature, this measurement has no relevance in relation to how the plant photosynthesizes usable light. If you want to take an almost 'true' picture of your plants I suggest lighting them with a mixed bank of High CRI, varying Kelvin bulbs. If you have to place the light a reasonable distance away from the application for whatever reason, I suggest taking lumen output in to account...

Phillips TL/950 98CRI 50Kelvin *CT* and decent *lumen* output mixed with Full spectrum 57k lamps with a near true *CRI*. Great for pictures~



If you are wanting to optimize your growing potential however, forget that any of the three terms above even exist...

/Plant Lights



The same lamp built for growing purposes will generally have a horrible visible spectrum to our eyes and look very 'purple.' It could be any visible color temperature, lumen output, CRI this simply holds no bearing. The bulbs 'PUR' ( Photosynthetic Usable Radiation ) is a measurement of actual emitted radiation by any particular lamp, this should really be one of the sole factors in taken in to account.

The myth of using various color temperature bulbs to stimulate variation in wavelength should be abolished.

The average store bought bulb no matter what the temperature of visible light recreated 30k-65k all do produce a varying amount of usable PUR/PAR it should be mentioned.

Hence the varying result people get from fluorescents.

No matter the spectrum of color brought out best due to CRI, light spectrum best represented by 'CT,' or massive lumen output created for wide area growing... I must compound by repeating...

These factors have little to do with actual usable radioactive wavelengths absorbed by the plant.

Thank you all so much for taking the time to read all this! Especially if you went right in to my first post ;D

~don't get lost in the fog dog
nol

[nolpenthes]

Now this link I feel really solidifies what I'm trying to get at.

;D

www.aquabotanic.com/lightcompare.htm

~Respect
nOL

[mikuláš]

Nol,
This is some interesting info re:indoor plant lighting. Perhaps you could share how you've translated this into practice with your own plants? That is, it looks like you use specialized lighting in your second photo?

[nolpenthes]

Thanks for the reply Mik, the bulbs in the second shot are a F32T8/PL (Plant) They are produced by a lighting wholesaler out of Vancouver called Standard Products.





These new bulbs will hopefully yield a solid result by optimizing usable PAR/PUR wavelengths at the sacrifice Lumen/CRI/Color Temperature. The plants seem to show steady growth over the last few days, the JR above doesn't seem to mind the swap. ;D

Only time will tell
~nol

[mikuláš]

Nol,
Do keep us updated on how your lights work out. I understand why you chose them (maximum PAR/PUR), but how did you determine that these bulbs provide the most PAR/PUR?

[nolpenthes]

The /Plant bulbs that I purchased were chose after some careful consideration and discussion with a lighting expert from my old job. Even after phoning the company directly though I could not get an accurate rating for either PAR or PUR out of them. Although assurance was given that they were a spitting image of current, optimal Wide Spectrum Plant lights. A couple things I do know about the bulbs are that this particular manufacturer does produce a very high quality item. Also that I would have had to wait weeks for any of the bulbs that I had PUR/PAR ratings for and have to buy them in case quantity due to the special order. This would have been an exuberant amount of cash and I'm not prepared to spend it on a theory

As I mentioned before in the post, I am not suggesting that people go and revamp their entire lighting system due to the fact that there may be a different way to do it on the market. A lot of the lighting that people have set up through research, fault or folly have a VERY adequate amount of PUR/PAR for photosynthesis.

However I strive to optimize.

My hopes are that people just read in to the post and possibly grab a better understanding of bulb effectiveness vs. bulb marketing efficiency. By no means do I want to come across as pretentious with all of this lighting talk, admittedly 95% of the people on this forum have a vastly larger knowledge base in regards to Nep's over myself.
Better put it's all just a little food for thought.
I am still trying to tack down the numbers (PUR/PAR) for the average 4' T5 HO lamp that is commonly sold as a 'grow light.' If anyone come across it in their travels I would much appreciate the link.

Much respect
~Nol

[rainforest]

I have never grown anything under lights (for the most part). But am now interested in using high output LED lighting because of the low heat out-put and the brightness that some multi light source LED's provide.
I would like to just put out these feelers in anyone actually trying and using these lights on an ongoing basis.
My use for these would be more for indoor lab use than growing these plants indoors.
M

[marka]

I bought some cheap Chinese made led's ufo and did a comparison against a 250w cfl grow light for six months. The led was 50w ( sold as 90w ufo, but that's another story) and had the 'wrong' red wavelength. In practice it held up very well against the cfl and is far superior to the equivalent wattage of T8 fluorescent grow lights.

I now run two 50w led growlights and have been very happy with the results. Only problem is colour if you want a nice display, and the fans are a little noisy.

White T8 led floresecent replacements are also getting cheaper over here and im sorely tempted to try a few of those as well.

[nolpenthes]

Yep, L.E.D's sure are making some huge advances in lighting. only disadvantages I can see are
A:) Cost for a decent model
B:) Light intensity, the grow logs I have seen show a lot of "stretching" by plants to attain reasonable light. The LED systems, as far as I know, have to be constantly adjusted to mm's above the plant to get optimal result. Huge payola for moderate results unless constantly monitored.

If you want to see what money can buy in respects to LED lighting, this is the company I'm keeping my eyes on...

www.kessil.com/

~peace
NOL