# Lighting theory vs experience



## Dr. Demento (Jul 26, 2007)

In Diana Walstad's book she mentions a study that showed that optimal plant growth was achieved using one VitaLite (full spectrum) & one cool-white (run o' the mill bulb) [The study Diana cites showed only slightly less growth for dual cool-white bulbs]. Her rationale behind the results were that aquatic plants had evolved over the millennia to utilize different frequencies of light than terrestrial plants.

The reason the aquatic chlorophyll evolved was that water absorbs lower frequencies (red/infrared - geeked-out explanation - http://www.lsbu.ac.uk/water/vibrat.html) and dissolved organics absorb in the high/blue spectrum (Google terms "dissolved organic light absorption").

The end result, it seems to me, is that our quest for specific bulbs is overall pointless and scientifically unfounded. Now, that's the theory; obviously, theory is often incomplete and many times things continue to work that fly in the face of theory. One POV pointed out to me was the aesthetic aspects of lighting - I completely agree with that.

I guess my contention is that it seems that we propogate our experience and teachings from other hobbyists without a firm grounding in what's really necessary in terms of lighting requirements (and I'm unaware of any solid science); please don't get me wrong - most (if not all) scientific fields are guilty of this. If there is science, please, I'd love to read and understand it.

So, what's everyones take/experience/two cents?? I guess my leanings as an iconoclast :twisted: is to attack cherished beliefs. However, as a scientist, I am open to different views. The end goal? A stab at the Truth.

Take care, y'all.


----------



## hoppycalif (Apr 7, 2005)

I don't doubt that some lighting is better than other lighting. But, I suspect the difference in plant growth that results is small, possibly too small to notice in an average aquarium. Clearly there are bulbs that are inappropriate for planted tanks - actinics, for one. But, for the average person, looking to have an attractive, satisfying planted aquarium, I think personal preference based on how it looks is the most significant thing. 

Some people enjoy looking for the best of whatever they are interested in, and enjoy testing to determine what the best is and why it is the best. Those people help all of us in making our decisions. 

Those are just my opinions, of course.


----------



## Aen (Jul 24, 2007)

Seems like Takashi Amano reccomends green light over blue and red.

*Quoted from Aqua Journal:*
In the tropical streams where aquatic plants grow, sunlight are filtered through many vertical layers of tree canopy. The upper layer receives as much as 25% to 100% direct exposure to sunlight. This is scientifically known as the euphotic layer. In the lower parts of the forest and streams below, where low light conditions occurs, this si known as the oligophotic layer where a mere 1-3 percent of light is made available to plants. This small percentage of light are filtered through the forest green canopy and reflected as incidental light, thus the natural wavelengths are dramatically altered. Aquatic plants have evolved millions of years to adapt to greenish light available to them. The NA-Lamp adopts a fresh green ulothrix fluorescent to reproduce nature's green irradiance wavelength in your aquarium.

Here's the spectral distribution of NA-Lamps.










So I guess land plants or those that get sunlight all teh time like red and blue, while those at the bottom and in water have evolved to make use of green better.


----------



## defdac (May 10, 2004)

Actinincs grows plants very good Hoppy, try it and see. They produce insanely amount of plant usable light.

Dr. Demento, read this article - I have and made a calculator out of it and experienced one of those enlightening moments where advanced theory meets reality in a very hand on experience when I exchange GroLux-bulbs with Aquarelles:
http://www.aquabotanic.com/lightcompare.htm

Here is my expanded list of PUR-efficiencies:
http://www.defblog.se/permalink/1402.html
And here is the beta of my calculator:
http://82.183.138.227/GTKTest/GTKTest.html

I've expanded the theory in the Ivo Busko-article quite a bit in my upcoming revision of the calculator - now I have frequency based attenuation (blue attenuates less for example), and also will have a kelvin legend where one can see the change in kelvin from top to bottom of the aquarium based on the frequency attenuation =)


----------



## hoppycalif (Apr 7, 2005)

I have no interest in using actinic light for anything, since I find it to be unnatural looking and hard on the eyes. Several years ago several people who were members of the Aquatic Plant Digest mail list did some experimenting with actinic light for their planted tanks. They all reported that they had to stop their tests since the plants were dieing (as I recall). Based on that I continue to believe that actinic light isn't suitable for plants.


----------



## defdac (May 10, 2004)

The plants would probably not elongate at all, only grow sideways. Perhaps they wrongly took that for they dying? Or perhaps just used to few bulbs? They cut out half of the usable energy by only using blue, so they need to double the amount bulbs I guess.
There are many references of growing plants with blue light only:
http://www.google.se/search?hl=en&q="blue+light+only"+growing+plants

Nothingn wrong with APD in general though. Ivo Busko was there regarding light =)


----------



## ruki (Jul 4, 2006)

Aen said:


> *Quoted from Aqua Journal:*
> In the tropical streams where aquatic plants grow, sunlight are filtered through many vertical layers of tree canopy. The upper layer receives as much as 25% to 100% direct exposure to sunlight. This is scientifically known as the euphotic layer. In the lower parts of the forest and streams below, where low light conditions occurs, this si known as the oligophotic layer where a mere 1-3 percent of light is made available to plants. This small percentage of light are filtered through the forest green canopy and reflected as incidental light, thus the natural wavelengths are dramatically altered. Aquatic plants have evolved millions of years to adapt to greenish light available to them. The NA-Lamp adopts a fresh green ulothrix fluorescent to reproduce nature's green irradiance wavelength in your aquarium.
> 
> Here's the spectral distribution of NA-Lamps.
> ...


If this is true, the molecules used for photosynthesis in aquatic plants would be different than those for terrestrial plants. This is a testable hypothesis. Has this test been done? If not, it might be probably closer to marketing hype than science. I'm skeptical, but very open to valid experimental data.

Here's an example. I have a very nice hygro compact fluorescent lamp that on the box claims it is much more efficient than metal halide. But no proof is given for this anywhere. I checked the manufacturer web site. No reference given to back up the claim. It does grow aquarium plants very well, but it's not any better than other high-end lamps. Its lighting footprint fits a 60 cube very well, so I plan on getting a replacement bulb from them. I still don't trust their claim though. When commercial greenhouses switch to this bulb, then I'll believe it


----------



## defdac (May 10, 2004)

> When commercial greenhouses switch to this bulb, then I'll believe it


They have sadly enough bought the hype of lumens and lux, so they most often use sodium-bulbs with only a big fat yellow spike in the spectral distribution. They get incredible amount of lux, but not much blue and red, which grows plants.


----------



## ruki (Jul 4, 2006)

defdac said:


> They have sadly enough bought the hype of lumens and lux, so they most often use sodium-bulbs with only a big fat yellow spike in the spectral distribution. They get incredible amount of lux, but not much blue and red, which grows plants.


Commercial greenhouses are about making profit and reducing costs, so there is an economic reason for them to use appropriate bulbs. There is huge promotion potential in someone taking responsibility for changing to more appropriate bulbs. So, there will be a switch to other bulbs if those bulbs are much better. I'm assuming it should have happened by now, but that assumption could be totally off base 

There is enough red in sodium bulbs to help out with producing blooms, so if you happen to sell flowering plants it is useful. A while back I stumbled upon something about how greenhouses change the mix of halide and sodium bulbs depending upon what they were trying to do.

I did notice that the University of Minnesota uses lots of sodium lights in their greenhouses on the St. Paul campus. I can see the red glow as I drive by on Larpenteur Avenue. But, I can't tell if the bulbs are the more expensive kind that have extra colors added. (Hmmm, there has to be someone there that has access to research data on bulb spectrum and plants. I know someone how works on that campus in another field, I'll have to ask about this sometime.)

One data point for GroLux: I had some extra space in a tub outside and some aquariums inside since the fish were outside, so I started some Micranthemum umbrosum emersed (baby tears) both inside and outside. The outside plant completely filled the pot forming an excellent ground cover. But no blooms even when using Peter's Professional root-and-bloom which does produce blooms for me in other outdoor plants. I'm still surprised that it did not bloom outside. The inside plants didn't grow nearly as well, but I did notice a flower, it was not much larger than a pin head. I'm thinking it's because of the deep reds in the GroLux tube. I used that and a Octron 6500K bulb, both being 2X overdriven in a modified fixture. When it gets cold outside, I can bring it in and see if blooms big time under the growLux tube for another data point.


----------



## defdac (May 10, 2004)

Yes I think you're right on Ruki. They most often want flowers and tall plants as they get with the type of bulbs they use.



> A while back I stumbled upon something about how greenhouses change the mix of halide and sodium bulbs depending upon what they were trying to do.


I do the same thing in my aquarium, but I've never heard of greenhouses doing the same thing. I've never seen a greenhouse with other than super-yellow sodium lamps, so I think most of them are a bit behind perhaps.


----------



## Endler Guy (Aug 19, 2007)

*Actinic turned my plants red in 3 hours!*



defdac said:


> Actinincs grows plants very good Hoppy, try it and see. They produce insanely amount of plant usable light.


I just came here and searched for "actinic" to see if anyone has had the same experience I've just now, this morning, had with them.

When I first decided to get into planted tanks, I unwittingly ordered 2 dual Sunpaq Satellight 2x65w, daylght & actinic. That was before I knew anything about planted aquaria. I've had them for a couple of months now but never turned the actinics on...until today! First, I only turned the actinics on and I didn't notice any bubbles from my vals. Then I turned the daylights on and soon started to see bubbles. I turned the daylights on and off a few times while leaving the actinics on. It looked like there was no photosynthesis happening in the vals with only the actinics. THIS IS THE GOOD PART. After only a few hours with both the daylights and the actinics on, my marble queen radican swords started showing red on the new leaf growth! They had NEVER been red, not even when I bought the mother plant was it red! The new leaf growth had been growing in white so I added ferts with iron and that only turned them a very light green.

Actinics are amazing! I plan on using them from now on but only along with the daylights as the actinic alone didn't seem to be enough for my plants. Besides, the daylights help mask the blue.

I'm still in awe over this!

I'm very interested in others' experiences with actinic. Please do tell.

Craig


----------



## rs79 (Dec 7, 2004)

If you think actinics are good, try another bulb. They're even better! That is, not matter what results you get with an actinic, if you stick in any other bulb you'll get better results. Promise.

There's lots of different bulbs and people have their favorites, but I say of all the different types of bulbs the best type is a NEW bulb. I'd take a new warm-white over an old whatever any time.

I've been trying to prove to myself different bulbs will produce a different response in plant growth - that there's one tube that just plain flat out makes plants grow better. For thirty years I just haven't noticed any difference in the color of bulb I use.

I only notice a difference in the wattage.

For abot 7 years I experimented putting every different type of 20W bulb over one 20 gal tank and while there were minor differences in legth of leaves, size, shape and color (the pink bulbs seemed to work best) the differences were minor. But when I put, instead, 80W of warm white light (despite the tubes being years old) the tank exploded. Wrong light, right response though.

I'm now convinced light color doesn't matter one bit and that light intensity is everything.


----------



## fishfan (Feb 19, 2006)

Before I started with live plants a few years ago, I was using one of those regular general electric fresh/saltwater strip light bulbs of 9325 K for one of my plastic plant only tanks. I stored it away when I began with live plants and sort of forgot about it in the desire to find the perfect plant or magic growth bulb. 

I finally gave up with this after awhile as I didn't like the look of my tank with some of these bulbs I tried. Out of boredom one day I dug out the old GE bulb that I had saved and put it on the tank. The plants began to perk up better than before in only a day and I found it created the perfect look (or color) I had always wanted for my planted aquarium.
I am surprised this bulb isn't more readily available at stores (at least where I live) with how nice it is.


----------



## rs79 (Dec 7, 2004)

New bulbs work better than old bulbs. If the bulb you put back didn't have that many hours on it (ie, only a month or two old) it's probably that than any spectral difference that accounts for the burst in growth.


----------

