# Sylvania GrowLux & Fluorescents



## Paph_LdyMacBeth (Sep 4, 2011)

Does anyone know the degrees Kelvin of the Sylvania Growlux bulbs? I cannot find this information. 
Is anyone using these -thoughts? 

I'm in the process of moving from my upstairs setup into a grow tent in the basement and I need to go 100% fluorescent. 
Currently I am using a 50:50 mixture of 4' warm & cool fluorescent, natural light, and supplemented with Sunblaster CFL's for high light plants.

I do have the option of using SunBlaster T5's, but I am looking to the Sylvania's as they are a significant savings. 
Any info is appreciated.


----------



## SlipperFan (Sep 4, 2011)

Does this help?
http://homeharvest.com/fluorescenttubes.htm


----------



## Hera (Sep 4, 2011)

Are the Sylvania T8? You would get more output for the money with the 
T5"s.


----------



## koshki (Sep 4, 2011)

I hope Ray sees this thread...ask him to post his chart on the difference between using warm and cool bulbs, vs using 6400 bulbs. 

I was convinced about using just the 6400 bulbs, after looking at his chart.


----------



## Sirius (Sep 4, 2011)

I would like to see that chart.

I have been using a 4 bulb T5 fixture for years above my succulents. I have two 6400k bulbs and two 3000k bulbs in it. The mix is supposed to support blooming and vegetative growth. 

I recently picked up some new shelves for my orchids, and bought several new T5 fixtures for the shelf. The bulbs in the new fixtures are all 6400k, and I was wondering if I should supplement with some 3000k bulbs or not.


----------



## Ricky (Sep 5, 2011)

Here is a wonderful comparison chart for all common types of light sources with the results in photosynthetic yield/Watt or PAR PPFD.
But it is in german, perhaps Google translate would help.
http://www.hereinspaziert.de/Sehlicht_2009/Ergebnisse.htm

As you can see here, Growlux is the weakest of fluorescent lights: http://www.hereinspaziert.de/Sehlicht_2009/Auswertung-LL_b.gif


----------



## TyroneGenade (Sep 5, 2011)

Go see http://www.apsa.co.za/board/index.php?topic=4454.0 . There is a lot of data on a lot of tubes. Seems that whole higher output from T5 doesn't hold up to scrutiny. What you can do with T5s is have a lot more in a smaller space. Also, the smaller tube means less light is lost to "squashing" of the light between the tube and reflector. You want to put more money into a good reflector than a tube. I think using a Warm white is A-OK. Gro-lux tubes have a lot of red light in the 660 wave length which can encourage leggy-growth. The Osram Biolux, Natura and Colorproof tubes have the most sun-like spectra with pretty much even spectral distribution between red to blue. The Osram Fluora also looks a good tube. While the data at the above link has been worked for aquarium use the basic principle stills seems to hold: the ratio of red to blue light seems the most critical to get good growth. The more yellow in the spectrum the less photosynthetically active radiation the tube is emitting. A high 660 to 640 ratio means leggy growth instead of compact growth.

Over my aquarium I'm using warm whites and daylight tubes. The results is much better than with the fancy Grolux and Aquastars I had over it before.

Hope this helps.


----------



## Paph_LdyMacBeth (Sep 5, 2011)

Sirius said:


> I recently picked up some new shelves for my orchids, and bought several new T5 fixtures for the shelf. The bulbs in the new fixtures are all 6400k, and I was wondering if I should supplement with some 3000k bulbs or not.



That's a great question. I know the SunBlaster T5's & I've been looking at are in this range also. They claim to be suitable for growth & flowering of orchids -although I presume they were intended for growing vegetative plants. SunBlaster has recently come out with "bloom booster" lower K bulb though which leads me to believe they are best mixed for blooms, but I would be curious to hear what more experienced growers think.


----------



## TyroneGenade (Sep 5, 2011)

A large peak at 660 would initiate flowering. This simulates "spring". The 660nm activates phytochrome which get the plant growing very nicely---i.e. leggy growth. Of course, most Paphs are winter flowering so the 660 nm does nothing for them as regards flowering. When it comes to lighting there isn't a one-size-fits-all option. You can probably grow the plants under lights with a large red spectrum and then, to flower them, expose them to lights with less red and more yellow and blue.

The K rating means very little. You must look at the spectrum of the tube and the PUR (photosynthetically useful radiation) rating. You want tubes with peaks spanning 400--460 and 600--640 nm but a Red:blue ratio of about 0.96 (tropical sunshine) or more. A small UV peak is beneficial.

P.S. Some plant biochemistry: Phytochrome Red (Pr) is activated to Phytochrome Far Red (Pfr) by light of 660 nm. This causes rapid growth (i.e. leggy growth). Light of 730 nm converts Pfr to Pr which is inactive. Grolux had a BIG peak at 660 but nothing at 730... So you get leggy growth. You want red peaks of about 620--640 to get neat compact growth.


----------



## Ray (Sep 6, 2011)

Just back from a weekend fishing trip to the New River in SW Virginia. Got the large fish of the group - a 5+# smallmouth. Only a record for me, but nice nonetheless.

Katherine is referring to the some plots of spectrum by color temperature, which demonstrates not only what wavelengths are emitted, but shows relative intensities, too. 







Folks mix bulbs because they need "red for blooming, and blue to growth", but there are a couple of things that can be taken from those plots:


The spectrum of the 6400° bulb most-closely matches the absorption spectrum of chlorophyll (blue intensity about 10-15% higher than red).
Not only does the 3000° bulb have almost no blue in its spectrum, but the intensity of the red is only about 2% of that from the 6400° bulb, suggesting that for the same wattage bulbs, you'd need 50 3000°K bulbs to match the output on ONE 6400°K bulb!

If you have Java enabled on your computer, you can play with the ap here: http://www.firstrays.com/bb1-1286570267-680/start/color_temp.htm to see the spectra of other light sources or specific color temperatures. The ap also gives you an approximation of the RGB components of white light, and what the combo might look like.


----------



## Clark (Sep 6, 2011)

Nice to know.


----------



## Hera (Sep 6, 2011)

Thanks Ray.


----------



## Ricky (Sep 6, 2011)

Ray, these spectrums didn´t really show the light levels of fluorescent bulbs, these are only theoretical spectrums of a "black body".

Here you can see the spectrums of common fluorescent bulbs (830, 840, 865), the difference lies in the red peak: http://www.hereinspaziert.de/Sehlicht_2009/LL_3B_b.gif


----------



## W. Beetus (Sep 6, 2011)

Great info. When I had fluorescent tubes, I also did the one red and one blue combination. I believe they were 2700k and 6500k. Good to know for future reference to skip the 2700k's!


----------



## TyroneGenade (Sep 7, 2011)

2700 K and 3000 K tubes (such as the warm whites) rock for plants. The blue peak is just where it has to be for photosynthesis and the red peak is at about 620 which is far enough away from 660 that you don't get leggy growth. If you look at the peak of the 830 you will see that you get about 60% of the light at that peak being photosynthetically useful but that red peak is almost twice the size of the blue peak meaning that you get about an even red-blue input. The red to blue ratio of sunlight is about 0.96 so you want even output for growth.

Summer flowering plants would need a strong 660 peak to initiate flowering. Winter flowering plants probably need a bigger blue input. Anyone know of any experiments done to initiate flowering in Paphs with artificial light? I recall a thread where someone put all their plants outside (from under lights) and suddenly they all started to flower. I wonder what tubes he was using...


----------



## Ray (Sep 7, 2011)

Ricky said:


> Ray, these spectrums didn´t really show the light levels of fluorescent bulbs, these are only theoretical spectrums of a "black body".
> ]


That's absolutely correct Ricky, but the phosphors are intended to match those spectra pretty closely.

Color temperature is an indication of energy level too, not just spectrum. More energy in = more energy out.

Think of an incandescent light bulb with an adjustable power supply - at very low levels, the filament glows dull red, emitting most of its energy as infrared (heat). Increase the power and it gets brighter and brighter, shifting more and more of its output to shorter, more energetic wavelengths.


----------



## Ernie (Sep 7, 2011)

My two cents...

We grew under fluorescents almost exclusively for many years before moving to FL. I found early in the game that under our conditions I was just as happy with our plants' performance using a 1:1 mix of warm and cool white tubes versus "full spectrum" or "gro-lux" or "agro" or "daylight tubes". In our case, we had a LOT of bulbs burning and replacing annually, so the economics also played a huge role. Warm/cool white tubes are $1-2 each, the others can be twice that or commonly much more. 

Not saying the 6400 K's aren't as good, on the contrary, they are very good bulbs, just saying the mix worked very well for us and for less $. Tricky part is that bub pricing and availability varies city to city. 

I also did a lot of spectrum research before settling on the tubes we used and was satisfied they were providing decent overall spectrum. You may see a big spectral difference between different manufacturers for similar type tubes. 

I also believe that bulb replacement schedule is just as important (maybe more so) than bulb choice. For T8s and T12s, their effective life for horticultural purposes is about 10-14 months roughly. They will light up "forever" sometimes, but their output drops tremendously after illuminating 12-16 hours/day for a year or so. Most folks are more likely to replace a cheap tube before burnout before a more pricy one. We rotated replacement to keep a fairly consistent output year-round. 

Just like all other aspects of culture, fake lighting is multidimensional (more to it than color (K) choice). It's bulb life, bulb length and diameter (volume), distance from plants, number of tubes, types of plants grown, daylength, etc.


----------



## Paph_LdyMacBeth (Sep 7, 2011)

All this information is great -truly! 
The difficult thing is trying to source information on what will work best vs what I can find. As Ernie said -it varies from city to city! 
I have not been happy with the "SunBlaster" 6 400K T5's thus far. @ 40+ each they just aren't matching up. I will continue to experiment with the few I have, but I'm thinkin' if I can't get my masdies happy with the lighting they're a loosing battle. 

It seems the hardware stores closest to me carry good variety of Phillips T8's. I've seen no other brands and this is what I am currently using. Does anyone have data on their bulbs?


----------



## Eric Muehlbauer (Sep 7, 2011)

I'm with Ernie. In my 4 bulb fixtures I use 3 cool whites and 1 warm white...the warms just never seem as bright as the cools. The plants do fine, but they tend to be mainly seedlings and brachy's.


----------



## SlipperFan (Sep 7, 2011)

www.nam.lighting.philips.com/us/ecatalog/catalogs/atoz.pdf


----------



## Ray (Sep 8, 2011)

Back when I grew exclusively under lights, I used 50/50 (wattage-wise) 40W T12 cool white fluorescent and 100W incandescent bulbs, and was very happy with it.

I have been growing some plants recently - mostly seedlings - under the Hydrofarm fixtures with their 6500° bulbs, and they are doing great too.


----------

