CF

[kenneth_kpe]

well im really researching into the CF's since i wanna switch from tubes to CF lighting. i just wanna ask if this is ok enough... its the best i could find locally ( if no i have to have lights imported which means expensive...)

its a 11W Compact fluorescent daylight running at 6000K

 

[kenneth_kpe]

the bulb on top had a CRI of 80 i think


this one is the one i want to have imported

it's running at 5,4000K and has a CRI of 90++

what do you guys think ?

 

[Lateral Line]

The second looks to have a better spectral makeup.

 

[Da_Oz]

I would go with the second. It seams to fall more into the range of most FW plants. But if it cost alot more the first should be fine for most low to mid light plants.

 

[kenneth_kpe]

yeah, the first one is available locally, and i mean at every hardware store, the second one i have to have imported via mail from germany

so is the price really worth it? the cost would be around 2times more.....

im not sure about my plants and their light requirements... my swords grew well with my present light which wasn't really a good plant bulb,

would riccia grow well with the first bulb ?

with both cases im gonna use around 45Watts of lighting over a 15gal......

 

[Silly me]

It seams to fall more into the range of most FW plants

I dont get that?

The second looks to have a better spectral makeup.

does that improve the growth? and if yes why??

First..

6000K doesnt mean much, its just the color the light look like when compared to a black boby heated to the same temp, example.. a piece of carbon heated to 2700K has a yellow to red glare, just like a warm white light, same goes for 6400K daylight tube/CF... sound good, but the main focus point of all light sold to light you office space and house is around the green or 550nm range, and the diffrence between 2700K and 6500K is a mix of red or both the create the color ( not spectrum.) and sometimes the colors that is used is not the right colors the plant can use..

Secondly LL said the second CF has a better spectral makeup..

looking at the picture it does full in all the gaps between the blue green and red.. So if the spike of red is too red or not enough there is lots of similar color around the spike to create a useable form if light for the plants.. so yes LL is 100% spot on

Does that improve plant growth, well some CF/tubes contain a yellow not a red substance ( forgot the name ) to probuce a unuseable color orange to plants. similair to sodium vapour but there is a lot of good blue in the first CF
but if the spikes is in the right useable red and blue with some green so I could see, you dont need a better spectral makeup.

so why is better spectral makeup better? well its just that some plant need a little more that just red, green and blue

so after all thats said and done. I would buy the first CF and use three 6000k light and mix a single 2700k light in. its just me..

the krib

>> Is it possible to say I have a 5000k light which corresponds to a certain
wavelength of light as measured in nanometers or is degrees Kelvin a
combination of spectrums as I would assume it would have to be if a 5000k
bulb is considered a full spectrum bulb.<<

No, the 5,000 Kelvin does not refer to a certain wavelength but the color
resulting from the mix of wavelengths. For example a Tungsten light can be
filtered and or burned hotter to create the 5,000 K color and it is full
spectrum. A flourescent bulb could have just three phosphors a red, green and
blue one to acheive a 5,000 K color. You can evalutuate the quality of the
flourescent bulbs by their CRI (Color Rendering Index). A bulb that has a
high CRI generally has a good number of and mixture of phosphors.

 

[kenneth_kpe]

this is the spectrum of the bulb im using now, its 7000K fluorescent tube 15W

 

[kenneth_kpe]

holy crap a reply before i could post mine ic ic so its safe to use the first one then, but wont 2,700 K be useless to plants ? but then again, im not really good at these things im gonna go with the first one or if possible try to look for a alternative second one but i doubt....

 

[Silly me]

before someone tell you the get a hight CRI.
from Richard J. Sexton <richard/aquaria.net>

I'm seeing a bunch of statements here about fluorescent tubes
that leave me shaking my head.

"Plant and aquarium" tubes are gro-lux wide spectrum. They're pink,
not yellow or orange. Regular gro lux is purple.

They have huge spikes in the red and blue ends of the spetrum,
almost no yellow or green and do not put out any energy in
non-visible ends of the spectrum. The cri is something like 65;
cri just means how close tosunlight it *appears* to the human
eye and has nothing todo with how well it will grow plants.

Chroma 50's emulate sunlight. The CRI should be a lot higher than
the numbers I've seen mentioned here. The C50 simulates noon
day equitorial sunlight. The C75 emulates noon day northern
sunlight.

I can't imagine what would make poeple think C50's or PL-AQ's
look "yellow" or "orange". A warm white might give you this
impression, but a C50 has a decidely blue tinge to it, and the
PLAQ's are quite pink.

I think some of you people are color blind!


- --
Richard J. Sexton richard@aquaria.net
Maitland House, Bannockburn, Ontario, Canada, K0K 1Y0 +1 (613) 473 1719

 

[kenneth_kpe]

ooo so CRI isn't the key..... os when im looking into plant bulbs i should be looking for color spikes where this is really complicated

 

[Lateral Line]

Silly Me:

The reason I would suggest that the second lamp whose spectra at the top was better is nothing to do with it's CRI - although for natural colouration, a high CRI is desirable.

Rather, I based my comment of the spectra themselves and a knowledge of the absorption spectra of the 2 principle chlorophyll moleculecular complexes.

Chlorophyll (a) has 2 similaly sized absorption bands, one centred about 410nm the other at about 775nm. Chlorophyll (b) has a large absorption spike at 470nm and a smaller, but significant one at 620nm.

The spectrum of the first lamp misses almost entirely the chlorophyll (a) 775 spike, whilst the second lamp has useful radiation at that wavelength.

Neither chlorophyll absorbs much radiation at all between 500 and 600nm, (that is why plants are green, that region is reflected), thus the high output in that region of the first lamp is wasted as far as plants are concerned.

A high CRI alone does not guarantee a good spectrum, but a very peaky one like the first can indicate a lot of useless energy being produced. Full spectrum lighting is better.

Chlorophyll absorption curves.

 

[kenneth_kpe]

well looking at what lateral line poted here
http/www.adrianxw.dk/personalsite/oddsan...hlorophyll.html

i scoured my catalog for osram lights and found this to be the best one... and i felt stupid afterwards because it read(bulb for plants and aquariums) hahaha

but its still a tube type......... and i think its really expensive haha

LL do you think its worth to actually tinker into these lighting things too much ? or should i just use the normal daylight bulbs and sit back ? or do good spectrum really make a biiiig difference... you know fluora compared to the normal daylight bulbs.... sorry about asking a lotta questions...


i found the chart you posted amusing because it hits the light to the smack

 

[Silly me]

Lateral Line. The last thing I said was that your were wrong? by al means I changed lots of my light setups to what you recomended others to do..
I also know the the absorption rate of the 410-425nm band is 5 times of that in the 775nm band.. ( I guess the deeper the water the less red gets there..) wouldn't that mean a bulb of no/very little red light would still work

kenneth_kpe, these light does have a great use but IME normal fullspectrum lights works just aswell, I cant see a better growth between the two?

 

[Lateral Line]

SM:

I agree with you entirely that red light is absorbed more then blue. If you consider the graph below however, even at 1m depth in clear water, there is substantial red light present. In the realms of the average aquaria, the effects of particulates and disolved chemicals are more significant - these mostly absorb at the high energy end of the spectrum.

The very red/blue peaky lamp Ken showed last may be good for plant growth, but in my experience, these kind of lamps make the tank look dark. There is little yellow/green light so little light for the plants to reflect. It may be good growth radiation, but not, I would suggest, good for viewing a display tank.

I agree, full spectrum is best.

 

[kenneth_kpe]

wait wait wait.. im starting to learn..... (kenneth is learning!!!).... but wait there is something i still cant understand... full spectrum lights are lights that have high Red green and blue right ? these are the lights that appear the brightest maybe ? full white i should say... so the first bulb is okay to use and i shouldn't bother about their spectrums too much ? did i understand correctly ? : ) i should compile everything that you guys posted here and make a general post haha

where can i get full spectrum lights ? are these your normal daylight bulbs ? whoooooooo head ache