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...

[Jon Parr]

Speaking of tomatoes...I don't know if you grew yours in dirt, hydro or AP, but I did learn a trick from Ryan Chatterson of AES at the conference. I quit growing tomatoes in AP this year, because frankly, they suck. I am so spoiled from eating insanely good tomatoes from our dry-farmed dirt garden that I just can't palate bland tomatoes. A tomato plant needs to dehydrate to "set" the sugars, and so far the taste of hydro and AP toms just doesn't cut it. I brought the question up to my local college, and they have found a way to get the taste back in hydro toms by increasing the nute strength to burn levels, effectively dehydrating the plant and setting the sugars. They didn't have any suggestions for AP. However, Ryan Chatterson gave a seminar on "what plants can be grown in AP", and when crenshaw melons came up on the projector, he informed us that he got sweet melons (previously unknown in AP) by scoring 1/4 of the vine right near the melon. He even tested the finished melons against those not scored on the same plant and found the scored melons were much sweeter (17 brix non-scored, 26 brix scored, I think). Methinks this same idea would work on toms. And it would allow the fruit itself to dehydrate without harming the rest of the plant. Cool. Gonna have to give toms another AP go-round.

Vlad Jovanovic said:

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'.

[Vlad Jovanovic]

They're outside in the dirt, fertigated with mostly humonia products and by products from struvite processing. Yeah, stressing the tom's a bit before and during ripening is an old trick I picked up in Holland. The hydro grower there would add NaCl at about 4000 micro-seimens to the nutrient solution. He equated it to "stress" and not dehydration, though what you say makes perfect sense...less water to 'dilute' the sugars, therefore a better taste/aroma.

In the dirt, with weather such as ours (extreme summer draught) 'dehydrating' them was damned easy. If I start to withhold water early fruit tends to be smaller, but still tasty.

Personally, I've not had much luck with getting tasty hydro tom's, but I haven't really tried all that much, or all that often. It always seemed like way too much in terms of energy since my hydro grows are almost always winter/indoor affairs.

Thanks a bunch for the tip on scoring the vines, I'll have to try that when the time comes.

I've noticed that my grapes are much sweeter in a drought year as opposed to a wet one too. Probably many sweet fruit bearing plants function similarly...As opposed to salad greens or cucmbers which seem to get real bitter when they don't have enough water...

[Vlad Jovanovic]

@ Julie in addition to the reply on the previous page (before Jon and I got to rambling off topic :)...Much of stuff that was sprouted indoors this past spring using PL-L's before being placed in the greenhouse, then out in the garden. While a new batch got the indoor treatment...

The taller and slightly sturdier seedlings received MH light. But the comparison is not really fair (110Watt PL-L's vs 250Watt MH). The very smallest seedlings at the front of the first photo had gotten only sunlight. The difference was pretty big. This allowed me to get a really good jump start when weather permitted, and an earlier first harvest when tomato prices were much higher...

I took these pics within a day or two, i think,  of putting them in the GH where they enjoyed a bit of supplemental night-time Phillips Son-T-Agro Plus.  I've not used the PL-L's or Son-T's since...because..well you know...the Sun is free and all...But as the Sun starts to dwindle and Autumn sets in to Winter, I'll put them back to use...

 

[Julie kirkwood]

Thanks for the update!

[Joe Bifano]

I know we are talking about your lights but I had tried 32 varieties of tomatoes in my AP setup and found that most of them were okay except for 2 varieties, sweet 100's and yellow cherry's I think were called golden perl's but have to check that for sure. They were fantastic the yellow tomatoes were like candy. My plants grew tall in the first part of the trough and got shorter and shorter as they got further away from the source. So I changed it to drain all the way and spread out the nutrients via holes in a new pipe.Now if they get better drainage next year and equal nutrients I am hoping they will be better, But stressing them via cutting a slit in the lower vine sounds good. I do remember that my Brandywine toms were a lot better in the ground in my old garden.