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...

[John Wroten]

I value your advice. I will look into the 400 watt MH. I suppose if I were to put in another 16 sq foot grow bed, I would need another light. The room is about 12 ft X20 ft. I am assuming I wouldn't have any trouble with a heat build up in the room, and if I raised cat fish and wouldn't  have to raise my water temp, I wouldn't have trouble with the moisture.

 My delay now is that I havn't used that portion of the basement in over 10 years, and it appears I have a mold problem. I am cutting out the bottom 4 feet of my paneling and dry wall, and taking them out. The carpet is all moldy and rotten. It is a mess. I am putting down ceramic tile now for the floors. If I stay with cat fish, and I know the floor temp in the winter is 60 F, do you think I should put down any insulation under the fish bed? Maybe 1/2 " blue board?

The web site you gave me for the MH, is that a good price, and if I go that way, how high should I place the light?

From the photos I see of yours, it looks like you grow enough food to feed a bunch. Do you have a large family, and what are your temps over there now?  Thanks ....John

Vlad Jovanovic said:

My personal opinion would be that you if you are already going spend that money on lighting you would (for a number of reasons be better off getting a complete 400Watt Metal Halide (or even combo, Matal Halide, High Pressure Sodium kit should you ever decide to flower things)... from here on we'll refer to them as MH or HPS lamps kit with a dimmable ballast.

1) - T-5's and their ballasts give off an extraordinary amount of heat actually. And if it's not a DIY project and your buying the T-5 as a fixture, your not going to isolate the ballasts like you would with the MH set up. Your pretty much stuck with all that heat. Great in the winter, not so much in the summer. With a MH set up you can very easily put the ballast in another room in the summer time, bring it into the grow area in the winter. Also, venting the heat from the bulb itself in the summer (should you need to) is a breeze. 

2) - You still need to replace all 4 of those tubes every 6 months or so, as opposed to about once every 2 years with the MH. Those are costs which really add up over just a couple of seasons.

3) - In reality, in an optimal scenario you would need two of those 4 tube T-5 set ups for a 4' x 4' grow bed. Whereas just one 400Watt MH set up is good for the same 16 sq. foot grow space (Especially if you are not growing very tall plants like tomatoes or medicinal marijuana).

4) - You have a dimmable ballast, so you don't need to use all 400 Watts at all times (Your 4 tube T-5 set up runs at about 220Watts, but then it will only take care of about half your grow bed). Depending on your grow schedule, cultivars and method this could come in handy.

http://www.amazon.com/Grow-Light-Hydroponic-Reflector-Comparable/dp...

Now, I can't vouch for this manufacturer as I use only Phillips brand ballasts and even bulbs, there are cheaper, as well as more expensive manufacturers out there, but for a 16 sq. foot grow bed in a basement, something of this type would be the way I'd go. My 2 cents. HID (High Intensity Discharge) lighting (MH and HPS is hands down absolutely the best lighting I've ever used to grow plants, and often the most cost effective.

In a temperate climate, I would personally would stay away from Talapia (or heating your water to 85 deg could very well give some stiff competition to your lighting as to which is your biggest cost to growing indoors

[Vlad Jovanovic]

Yup, unfortunately you'd need another light if you add another grow bed.

It certainly would do no harm to insulate. The tile may (mine is because of the outside walls) be slightly colder than the floor (air) temp (if you were meaning the air temp at floor level). As students (20 years ago) we used to scrounge the Dow blue board from construction sites (easy to sculpt mock-ups/prototypes blabla...), but I don't know what it's like anymore in the states in that regard?   

Sorry to hear about your mold problems, that can sure be a drag...

I'd keep a 400Watt light between 3 and 4 feet away to start with,  with seedlings. If you are not seeding directly into the grow bed, and are using tightly spaced grow trays or whatever,  you could dim that down (to like 50%) and place the light a bit closer (18" to 24") if you put your hand where the seedlings/plants are and your skin is hot, then it's too hot for them. Raise the light a bit or use a small fan. Since you are growing indoors you'll need some fans anyways. You can place a small fan to blow across the bottom of the bulb. Good ventilation is important, and will go a long ways in helping with plant mold/fungus problems. Also an oscillating fan gently blowing across your plants helps them build up tissue growth, esp. stems... (sort of like what happens to muscle tissue when you lift weights)...

Thanks, but I don't grow nearly enough! No big Family, just me and the Missus. 

Our temps at the were great until about 3 weeks ago when a freaky cold spell blew in with tons of snow (been snowed in here for a while now) howling winds and temps ranging from -15 to -25. I left my house once in the last couple of weeks and regretted doing so. Got stuck for almost a day and a half before I made it back :)

[Jon Parr]

Here's my advice: use a CMH bulb. These rock. Better IMO than HPS or MH. They are full spectrum, including some UV, and burn much cooler than all HID and flouros.

http://advancedtechlighting.com/cdmed18.htm

$69 ballast, $52 for bulb, another $15 for a socket. Keep in mind that the flouro fixture must he placed over the produce, blocking your natural window light. HID can by placed far enough above and to the side to allow natural light.

400 watt CMH bulbs run in HPS magnetic ballasts only. Mag ballasts are only 85-90% efficient, meaning they create 10-15% heat. Locate the ballast under the FT, or put ballast in a heavy duty bag and drop it in the FT, and use that 40-60 watts of heat to your advantage. The light will heat the basement air, lowering RH, and helping keep mold in check. Don't ignore ventilation, and pass intake and exhaust air through a heat exchanger helps conserve energy. Basement heat is used by the house anyway, so no real loss there.

Vlad, I'm digging my pl-l's. I'm surprised by how hot they run. And how cool the ballast runs. I haven't actually integrated them yet, busy busy.

Still, HID is cheaper on every angle; initial investment, power consumption, and bulb replacement, and plant performance.

[John Wroten]

The thermometer is setting on the floor leaning against the wall, so the 60 F is the air temp. If I walk on the floor bare footed, my feet get very cold, so this is why I thought of insulating the bottom of the fish tank. Blue board is only R3 but I think it would have to help.

This light you sugested and said if I were to grow flowered plants, as well as cool weather plants,it would help. Do you think I could grow tomatoes and peppers in 60F air, and about the same water temp? That would be great, but I thought tomatoes needed to be warmer.

As far as weather, I thought we were going to go from fall to spring with no winter. The coldest it has been was in the mid 20's at night, and into the 40's in the day, but we got our winter last night. 13 F this morning, with a high of 22 F today. Predicted 13 again tonight. I'm glad we didn't get your snow. You can keep it...John

Vlad Jovanovic said:

Yup, unfortunately you'd need another light if you add another grow bed.

It certainly would do no harm to insulate. The tile may (mine is because of the outside walls) be slightly colder than the floor (air) temp (if you were meaning the air temp at floor level). As students (20 years ago) we used to scrounge the Dow blue board from construction sites (easy to sculpt mock-ups/prototypes blabla...), but I don't know what it's like anymore in the states in that regard?   

Sorry to hear about your mold problems, that can sure be a drag...

I'd keep a 400Watt light between 3 and 4 feet away to start with,  with seedlings. If you are not seeding directly into the grow bed, and are using tightly spaced grow trays or whatever,  you could dim that down (to like 50%) and place the light a bit closer (18" to 24") if you put your hand where the seedlings/plants are and your skin is hot, then it's too hot for them. Raise the light a bit or use a small fan. Since you are growing indoors you'll need some fans anyways. You can place a small fan to blow across the bottom of the bulb. Good ventilation is important, and will go a long ways in helping with plant mold/fungus problems. Also an oscillating fan gently blowing across your plants helps them build up tissue growth, esp. stems... (sort of like what happens to muscle tissue when you lift weights)...

Thanks, but I don't grow nearly enough! No big Family, just me and the Missus. 

Our temps at the were great until about 3 weeks ago when a freaky cold spell blew in with tons of snow (been snowed in here for a while now) howling winds and temps ranging from -15 to -25. I left my house once in the last couple of weeks and regretted doing so. Got stuck for almost a day and a half before I made it back

[Vlad Jovanovic]

Yeah, insulation is rarely a bad idea. 

CMH is a good way to go too...Keep in mind John you'll still need a reflector, hangers, chords etc...Not exactly breakin the bank items though...

Lots of good suggestions there Jon. Though I'd probably be too chickenshit to put the ballast in my tank. Still, not a bad idea at all (me and Mr.Murphy are pretty close, which is why personally, in my case I would opt out).

I'm kind of a fan of magnetic ballasts, (I have 5 of them) call me old school. But I can see how someone might not want to use a ballast on full power at all times. Other than being dimmable, I'd always go with a hundred miles of wound copper over some silicone and transistors. Guess I'm an old fart too! :)

As far as peppers and toms...I don't think your air temps will stay 60 for long :) That might be a bit cooler than cooler than toms like, but if you were careful about choosing the variety, and your lights will certainly add some heat, it could work. Also, toms require a certain difference in high/low (day/night) temps to flower. It is certainly doable, but far from the (relatively) relaxed and hassle free growing of lettuce. Peppers I usually don't even bother switching the MH out to HPS. They seem to flower just fine with MH. (Sometimes I'll throw in the HPS for the heck of it, but I've certainly not found it necessary).

Both Toms and peppers are 'day neutral plants', so they will flower regardless of the amount of light or dark (photoperiodism). Instead, they'll just flower when they reach a certain age or phase in development (pepper) or in the case of tomatoes, will respond to other environmental stimuli, like a period of low temps followed by a period of high temps...

Jon, I've noticed that my PL-L's seem to have cooled down quite a bit from the first few weeks that they were running. If you could take a temp reading to compare with later (since I did not) or even a mental note of how hot they are (since it's not that important, just the difference seems pretty big) it'd be appreciated...

Btw...The PL-L peppers are also flowering beautifully without any changing of the tubes to a 'warmer' Kelvin rating :)

[Jon Parr]

I'll measure the temps Vlad. I use vertical bulbs where I can, so no reflectors. Even crops like lettuce can be grown vertically in towers. Diy reflectors can be made from sheet metal, or aluminum flashing. Flat white titanium paint reflects about as much as the best commercial reflectors, even more than mirrors (which seems hard to believe).

I was afraid to sink my ballast too, but so far so good. I just used a single heavy duty trash bag, and the top of the bag hangs over the top and points back downward, so that any stray water can't chase the cord back to the ballast.

I have 13 400 watt mag ballasts, and 2 1000 watters. Unfortunately, all my 400's are integrated ballast/fixtures (old gym lights and street lights).

[Brent Wheeler]

Jon Parr said:

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.

[Brent Wheeler]

your idea of the ballasts heating the FT is not to far out.... wish I had seen this before I set up my system...  IF your place your FT on cinder blocks and place your ballasts in the blocks that would heat the blocks and in turn the FT....  

Could you provide a photo of your lights?  I have several types I am trying out and the HIDS all use hoods..  the idea of being able to hang a bulb and use a fan to keep plants safe is interesting....   my hoods are enclosed and soon will be vented outside..  with the option of venting inside for the winter,,,,,

[Julie kirkwood]

Hi Vlad - do you have an update on your PL-Ls? I see you've had them for nearly a year now

[Vlad Jovanovic]

Hey Julie,

I'm still really happy with them. Though I haven't used them (or any artificial lighting) much at all over the summer. This early-mid spring they did well helping many a seedling (hundreds)  get the jump on some veg growth before being put outside in the garden. I will be using them again this winter for some indoor grows. So far so good.

[Jon Parr]

I see I missed Brent's post back in July. Oops. Yes, Brent, I'll snap photos of my lights, but not for another month or so, because I don't use them in the summer. Btw, Vlad, I still haven't used my pl-l's, but will soon. Time flies. And...you were missed at the AP conference. I hung out with Matt Ferrel one evening, and we decided we should sponser a fundraiser to get your and your lovely lady to the next one.

[Vlad Jovanovic]

Hehe...Tanks Jon. (ommission accidental, but I'm leaving it be :) You guys both are too kind. Yeah, it would have taken a lot of tomatoes to get to Denver. Sure would have been cool beyond words to get to see and hang out with everyone 'in the flesh'.