PL-L Lighting

[Vlad Jovanovic]

In an ideal world, you would have a fluoro tube with all the advantages and none of the disadvantages of current fluoros. Our ideal fluorescent lamp would have a relatively short, compact, flat profile, massive lumen output with excellent lumen maintenance (meaning fewer replacement tubes), cool running, low replacement lamp costs, be available in all common spectrums, and fairly cheap to setup...

Enter the "PL" Lamp.

I first noticed these things when some local street-lights got changed. All serious indoor growers can tell you the exact type and wattage of any given street-light, and these things I didn't recognise at all, but was immediately drawn to the a), beautiful colour of the light. The CRI is very high; the red and green car parked beneath were, red and green, and b), intensity of the light; where the old 75W HPS streetlights ended and this new 55W PL fluoro streetlight began was the border of two totally different worlds, one dreary and yellow, the other vibrant and clear. I got home and Googled for a long time.

High CRI might not seem important, but a low CRI will mean a lamp is gaining it's lumens ratings, and colour temperature from fewer, more pronounced "spikes". High CRI means the lamp will have a wide mix of phosphors, and a more even spectral distribution, which plants will enjoy.

They are called by many names, "Dulux L", PL-L, LYNX L, LYNX-LE, PLL, High Lumen Biax L, PL, FT, FDTL, etc, but are all the same beast; a flatish, 4 pin [2G11 base] fluoro [triphosphor as standard] lamp of two improved T5HO-like parallel tubes joined ("kissed") at the end (aka "single turn", or "U-Bend"). Technically, it's a CFL lamp. 

PL tubes are available in Colour temperatures from 2700K ("Very warm white, aka. "Interna", "Home Light", etc.) to 6500K ("daylight"), are 'very' intense, cool running, long-lived, and produce a lot of useful lumen, overtaking the T5 as the most luminous small fluorescent. 

To get usable lumen in a two foot space with T5's, you'd need to use two 22" (24W) tubes, giving you 4,000 lumen. The smaller two 55W PL tube will give you 9,600 lumen of more intense light, with a smaller lamp size, and better penetration...and the bulbs literally cost a few dollars.

Judging by the online catalogues I've seen, these things are gaining some traction in the vivarium market, and 55W versions have popped up for "deep vivaria", and are sold for plants with high light requirements. And if that wasn't good enough, wait for it...

An 80W PL tube has recently appeared on the scene, blowing away all the previous numbers. For only another 35mm length, you get 1200 more lumen! 

T5's just can't compete with PL80W lamps for sheer lumen-per-inch; we're getting into serious HPS intensity competition territory, except with better spectrum, higher PAR, 'cooler' running lamps, way stealthier profile, etcetera...

Anyways...as of right now I've only got a bunch of little sprouts under these 110Watt PL-L's, but will see how they do when the Habeneros and Fefferones get a bit bigger...

[Eric Warwick]

Could you show us a reputable company that sells them? Thanks for the lighting tip;  I'm going to google these bulbs now! 

[Eric Warwick]

http://envirolightusa.com/articles/2.html I'm thinking these people would like to sell their product, as it does not seem to be balanced. But, what do you make of this article. I'm thinking it only is true in the lighting business not the growing business, but I'm not sure.

[Vlad Jovanovic]

Yeah, you're right the article doesn't seem balanced at all...Firstly I'm thinking that the PL lamps they're talking about may be different from the PL-L fixtures? Also, most all the gripes they seem have with PL also hold true for floro tube fixtures in general, T-8's T-5's HO T-5's ect...That is, being "locked in" to a certain type of tube at a certain Wattage...Or, how much 'easier' it is to change out ("just screw it in! No electrician needed!") the GU24 style...

I don't know, I didn't exactly need to call an electrician for these pups, just popped 'em in, pretty str8 forward...

I think that article is coming from a totally different angle (and with a totally different purpose) than is relevant to my plants...

I think for grow light type applications they should be pretty keen (and do come in a variety of Kelvin flavors, even though that article alluded to otherwise)...

As far as a reputable company goes, well your probably better off than I am. Most everything here (where I live) of this nature comes from either Germany or China, and these days even the German stuff is actually being built in China. So you probably have some better choices Stateside. (The bulbs you can get from just about any reputable manufacturer, Phillips, Osram, GE etc)...The fixture I purchased has a dimpled metal reflector backing, is white and has absolutely no other markings or branding anywhere on the outside so I have no idea who the maker/re-packager of my particular fixture is...

[Vlad Jovanovic]

Here is what's going on so far...

This pic above is actually from 2 days ago...but this is what the PL-L rig looks like...

 ...and the 4 pin base 2G11 base with the tubes plugged in... (above pic)

...the other end of the tubes where they are joined together with a kiss. So, technically speaking this is a CFL lamp.

This pic is from today, it's getting REALLY crowded, i figured the spinach (middle left; theres more of it in the back of the photo, but it's view is obscured) would have wanted to begin bolting by now (so's that I could get it out of there, toss it in a salad, and create a bit more room for the other plants) but so far it hasn't?

 Temperature, when the 'box' is closed up with one small vents open... (cheapie Arduino uno and DHT11 sensor)...and still no bolting 'cold temp loving' spinach? 

These sea of Hab's and Fefferoni's (hence why I try to keep the temps up since they are my main concern here) were aslo under the PL-L until I re-potted them in bigger net pots 2 days ago...

Becuse you can get things to sprout with a freakin' birthday cake candle...In a few weeks time I would like to divide the box with a light blocking material and try to flower some hot peppers with the PL-L on one side, and my 250 HPS set-up on the other (not really  a fair comparison, I know but comparison is not the point here)... I will try to put in one 3000k or even 2700k 55Watt PL-L tube and leave one of the existing 5000k tubes in there, for flowering/fruiting. Just to see what this rig can really do. The tubes are only like $4 USD here...So far I'm really happy, and I don't have to keep this light so damn close to my plant's like with the comparably priced T-8's! (T-8 like prices, with T-5HO like output...hopefully this will be a winner)...If nothing else, it seems that it would be great for clones, seedling, and leafy greens (surely til full maturity picking time leafy greens, based on the numbers and what I'm seeing so far with this light)...

[Eric Warwick]

Hey Vlad, one questions: what's the reflector for your PL-L bulbs made of? How much did it cost?

[Vlad Jovanovic]

The reflector itself is dimpled aluminum...The white vented housing is steel. I picked it up for 4,800 serbian dinars :) (like 70 bucks U.S).. If I lived somewhere where I could just order exactly what I want/need, I'd probably get something like this...

http://www.ahsupply.com/36-55w.htm

I'd forgo the housing and broad flat reflector, and opt for a better reflector design, just to get as much as I could out of the light itself. Though it seems to be working fine as is...  

[Vlad Jovanovic]

Day 18 under the PL-L... Ok, so even though somehow the spinach isn't bolting, I decided to get it out of there...

Three plants 66 grams of edible leaf. and 72.64 grams of just roots, and stems. (probably a tiny bit more as some was tore out and stuck to the net pot and hydroton). 

  

[Jon Parr]

Hey Vlad. You have me thinking about these pl lights. So, I despise reflectors and wasted light, so flouros have always been low on my list of options. But these pl-l's can be hung from one end, and used vertically. It was tough finding fixtures for them, too bad I didn't see your link above before I started hunting. Anyway, I found a 220 watt ballast, sockets, and bulbs at 1000bulbs. It seems easy enough to wire them, and I found a tutorial if anyone needs it. The ballast is about $50, sockets $10 for 4, and 55w pl-l $40 for 4, totaling about $100. Double that, to compare to HPS, and you get $200 for 440 watts, 8 pl-l bulbs, and 38,400 lumens. Not bad, much cheaper than t5's, a little cheaper than t8's. I also found some 80w pl-l bulbs for $13 and 6,000 lumens each. If you could use a 220w ballast to stretch 240w for three 80's, then you could bump up to 36,000 lumens. To compare; 400w HPS ballast kits are $70, socket $10, and bulb $20, totals $100 for 400 watts, 1 bulb, and 50,000 lumens, or about half price. 400 watt CMH would total $130, 1 bulb, and 36,000 lumens. LED's are out of the ballpark, not even in the running, IMO.

I know lumens are a poor measure of performance value in plants, so let's call the lumens a wash, assuming equal usable light. Bulb life: pl-l 55w is 12k hrs, pl-l 80w is 20k hrs, 400w CMH 15-20k hrs, and HPS is 20-24k hrs. HPS is hard to beat, but I do like the idea of hanging some pl-l's amongst the plants, rather than arranging my plants around the hot bulbs of HPS. If artificial light were the only source of light, I'd choose HPS. However in a wintertime greenhouse, I think I'd choose pl-l's to brighten up the jungle.

Btw, HPS gets cheaper as you get larger. 600w is the sweet spot for l/w at 90,000 lumens, and $150-200 for bulb, socket and ballast. 1000w gets 140,000 lumens for $200-250.

[Vlad Jovanovic]

Hi Jon, 

Nice breakdown on the prices/watts/lumens, ( I like you, believe that looking at just the lumen output is a poor way, when used by itself, to rate a lights potential in horticultural applications. Our lights do not have human eyes so a lumen may mean very little. PAR on the other hand...). I agree that HPS is sure hard to beat, especially for (but not only) sheer lumen output), and I am counting on their heat in my scheme of winter greenhouse heating. Electricity here at night is 4.3 times cheaper than from 8:00am till midnight. Obviously, they wont be the only source of heat in a 2131 sq.ft GH, but I'm coming to find that they are a much more significant source of potential heat if one "creates a space within a space" bubble-wrap/hoop house lining, or some such insulation...

You are absolutely right in that PL-L's could be used vertically and without reflectors. They still give off a bit of heat though (nothing compared to HPS, and especially MH), and most of the heat they do give off seems to come from near the 2G11 base...

Do you use any vertical/reflectorl-ess air cooling products to help with the heat from your HPS's? Might be worth looking into, or even making yourself? 

Please link the tutorial you found...These PL-L's certainly do seem worth at least looking into. Prices here are a bit different than your area but not by much...

[Jon Parr]

I don't have any issues with excess heat when used vertically. 400w HPS cool themselves, and I have leaves within 6 inches from the bulb with no burn. The heat that the bulb gives off creates a very localized updraft near the bulb and a cooling effect. Fans at the ceiling blow warmth back down across the plants and fish. I use a small fan on the floor pointed straight up under 1000w HPS, and have no heat issues outside of 12". Reflectors cause the heat to be retained, and I've seen heat burns on plants 4' away from a horizontal bulb from reflector magnification.

Also, HPS are the most efficient in in lumens per watt, so I believe they create the least heat per watt, just concentrated. If you where to put different style lights of equal wattage in a cooler, and measure cooler temps after an hour, I would guess HPS to be the coolest? Would be a fun and controversial experiment. Hmmm

Speaking of relying on byproduct heat, it aggregates me to no end to use electric heaters in fish tanks, when lights produce so much of both. I wish someone would make waterproof ballasts that we could drop into the tanks to salvage that heat simply. Maybe I should place my fish tanks high near the ceiling to absorb room heat, with ballast, lights and plants below. That was my first plan when setting up, but logistics of elevating FT's is significant. And of course, the FT's get the sunlight instead of the plants. Would be nice to have a reversible system for summer/winter. Nice picking your brain, Vlad.

[Jon Parr]

Link:

http://www.icmag.com/ic/showthread.php?t=112670

It's a cannabis site, all the good ones are. Hope you don't mind. :D :D

[Eric Warwick]

The stoners where funny!

Jon Parr said:

Link:

http://www.icmag.com/ic/showthread.php?t=112670

It's a cannabis site, all the good ones are. Hope you don't mind.