Lighting Question

[JenCliBee]

I think you trying to be a little picky now jake, you also cannot ask questions in your post and not expect a reply, with everything in life there is a optimal ranges, as you stated above the optimal range isn't 6-8k in fact there may be no optimal range! However if you read the thread provided, you'll find the scientific evidence from good sources. Not done by Hagen or jbl. I don't understand how you cannot take barr's opinion/fact as he has done the experiments that you are looking for. What we do know is tha k ratings are purely and simply for asctetics.

Again sorry to the op, personally if you want a warm looking tank go for 6000k and 9000k, if it's crisp the head for 9000k. Anything over this however looks to marine IMO.

WOW!!!, picky isn't what i would actually call it, more trying to get a perceived attitude to an answer that simply has no scientific conclusion.

This will be the last comment made by me because it is going nowhere fast and the end conclusion on my side and yours by the sound of it will be exactly the same.

But......

It was you that originally came out with kelvin reading have no effect whatsoever. That was a straight bold statement then not very well backed up by none scientific quotes.

Actually what Tom has stated was that he didn't see or the data showed no significant difference in plant growth no matter what K rating was used..... i never questioned this at any point in this thread. I never said you must have this K reading or that K reading bulb i mearly stated in IMO that a naturally occurring sunlight tube would probably have more optimal values than it would any other tubes, however the info you linked to was an interesting read and very informative..... did you actually read it?, did you understand what what said?....

plants photosynthesize better with blue and red emitting bulbs/light/radiation/waves which ever way you want to put it... the range i suggest is high in red and blue light so was my understanding that this was infact the best or 'optimal bulb' which would give out the highest PAR reading where infact blue..ie.. atinic and direct red does so in theory this would be far better for plant growth than anything else.. yes even blue but as you would imagine direct red or direct blue would be the best optimal viewing lights so basic compensation would have to be done with the aesthetic look as you've mentioned.

just remember why this thread ended in this manner, wasn't me that said out right K ratings don't matter, that was you... i didn't state that plant's growth would be different or better under any bulb, i didn't state that he has to get this rating bulb, i advised on the 'possible' optimum that my conclusion came to. I never said you were wrong, i also never said i was right because unless proper testing in depth is done only speculation and personal experience can tell you but that doesn't mean you are correct because of it that just means you have an opinion like everybody else..... so after all that i don't think i was been picky in the slightest just merely trying to get over to you... the plant mod!!! that not everything somebody says no matter how well known in the aquatic world they are is completely and utterly correct because they say so ....now if he had tested each K rating bulb and then gave accurate reading's to find which does emit the highest PAR reading then that would actually equate to testing and knowing for sure, unfortunately he didn't, nor did you and nor have i so please don't dam right dismiss somebody else's opinion when all this is just pretty much based on them even the OPINIONS of the god you think Tom is.

 

[ian]

shall we wind this back to beginning, Jake?

aim for 6500k-8000k for optimum plant growth

my answer

Plants don't care about the K rating of a bulb, this is a old myth, they are more reliant on the PAR of a bulb, PAR is a measure of how much light there is within the photosynthetic range. The K of a bulb is purely aesthetic, on my main planted tank i run 2 9000k and it looks crisp.

Now, tell me the optimum range?

There is no optimum range?

This is fact, not opinion. I am not dismissing any opinion, as this is fact. The proof is in that thread i gave you above, i'm not going to copy and paste every scientific piece of evidence, as you are completely able to read it for yourself.

As for Tom, i don't hold him in any god like status, as you may think, i have respect for him as he is a pioneer in this circle. I also have experience with the sales blurb you'll read regarding K ratings and growing plants under different ratings. Like i said in the above, i don't claim to be a clive or tom.

Now, I suggest you read the thread back, i did see you edited a post and please keep this debate civil, Jake.

 

[lljdma06]

Scottca, I like the bulb choice. I end up mixing as well. I like tanks to look "warm". IMO, there are far more important things to get right with planted tanks than what bulb you end up using. as long as you have a bulb that doesnt give off too much heat, which is why we don't use incadescent bulbs. For me, flow trumps light. More often than not, I'll ask about flow first now, but that's just me. You go as far into details as you want to go... Me, I don't care so much about these things.

This debate is interesting. Ian, can you link to the Barr report on this? I think you two are kind of saying the same thing, but too much attention, IMO, is being paid to very small details that will ultimately not have much of an impact on the hobbiest's ability to grow plants. Sorry, I just don't approach the hobby in the same way. I don't even know the color temp of the bulbs in my new scape. The plants are growing great. Tank looks pretty, I'm satisfied.

Justy two cents worth.

Liz

 

[ian]

The Barr report link is ^^^up there, it is 49 pages long, hence why i didn't link everything. I agree we are saying almost the same thing, however, when talking about K ratings of bulbs, we need to get away from sales blurb regarding which K provides better plant growth as every tube on the market will grow plants, whether it be 14000 - 4000.

 

[lljdma06]

Thanks, I'm old & missed the link... Will grab some beers maybe this weekend & have a good read.

 

[mbsqw1d]

i read somewhere once that my elodea densa would grow differently under different K intensity:

long and stringy under high (blue-ish) K and short and fuller under lower (red-ish) K.
is this garbage? lol

 

[ian]

elodea densa will grow under any light, it is one of those bomb proof plants, again i really can't see the K of a bulb making something grow shorter, as elodea will always normally reach the top of any tank. It'll be the PAR of the bulb which dictates whether the plants get leggy.

 

[lljdma06]

With Egeria densa, I have personally found that temperature has more of an effect on its particular growth pattern. Colder temperatures will bring out fuller, darker growth, while warmer temperatures will make the growth lighter and less full. But this has just been my observation.

Liz

 

[JoshuaA]

With Egeria densa, I have personally found that temperature has more of an effect on its particular growth pattern. Colder temperatures will bring out fuller, darker growth, while warmer temperatures will make the growth lighter and less full. But this has just been my observation.

Liz

Interesting, I noticed something similar when changing my girlfriends bulb to a "warmer" one. T8 and 15w no change in energy output just temperature.

I know this is controversial but if someone wanted to grow a certain plant for a certain use... ( I don't ). Why do they always use Sodium bulbs for optimum growth?

 

[ian]

I think and don't quote me, it has something to do with the PAR of the bulb, sodium bulbs have the best PAR you can get (i think), which in turn would trigger the growth. They also come in a massive wattage. Like i say i'm no lighting specialist, we could do with AC!

 

[lljdma06]

With Egeria densa, I have personally found that temperature has more of an effect on its particular growth pattern. Colder temperatures will bring out fuller, darker growth, while warmer temperatures will make the growth lighter and less full. But this has just been my observation.

Liz

Oh, I should clarify. I mean temperature with heat not light. Warmer water, stringy growth, colder water more lush growth.

Sorry, I can see how people would be confused by my statement espcially since we're discussing colour temperature. I mean water temp not colour temp.

Liz

 

[JoshuaA]

All my Egeria densa has come found the same stem from my friend but when I gave my girlfriend some her's did change completely when changing the bulb, the bulb was the same wattage etc.

I think and don't quote me, it has something to do with the PAR of the bulb, sodium bulbs have the best PAR you can get (i think), which in turn would trigger the growth. They also come in a massive wattage. Like i say i'm no lighting specialist, we could do with AC!

Haha should see some serious plant growth under the street lights then , just kidding.

 

[Bignose]

from the Wikipedia article on PAR:

Photosynthetically active radiation, often abbreviated PAR, designates the spectral range (wave band) of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less with the range of light visible to the human eye. Photons at shorter wavelengths tend to be so energetic that they can be damaging to cells and tissues, but are mostly filtered out by the ozone layer in the stratosphere. Photons at longer wavelengths do not carry enough energy to allow photosynthesis to take place.

In other words, if you can see the light coming from a bulb, the frequency of the photon is such that a plant can make use of it. And if you can see the light, then to a plant, a photon is a photon is a photon. What is needed for optimum growth is an abundance of photons in order for the photosynthesis reactions to take place -- not photons that are a few nm different in frequency. It is the amount of photons, not their specific frequency that is far, far, far more important.