6700k?

[ouchia]

does anyone know if 6700k is ok for a planted tank? i read that 6500 was the highest, but what's with the coralife 6700k bulbs then? i'm switching from a 10,000k bulb. is the difference going to be substantial? anyone know?
ps... i'm looking for more horizontal, "bushy" growth more than height...

 

[Bangin]

The 6,700k will be great. That's what I use for my tanks. You'll definitely see a difference between the 10,000k and 6,700k bulbs. Just be sure to have enough wattage for the results that you want.

 

[ouchia]

ahh.. thanks... one more question... someone told me that if i used a 10,000k bulb i would get more bushy growth, but with 6700 i'd get more "height". is this true? i also heard that i will get no growth with 10,000k, so i don't know...

 

[endparenthesis]

I don't have any experience with 10,000K bulbs... but I'm pretty sure they're better for marine tanks than freshwater.

 

[mrV]

I don't have any experience with 10,000K bulbs... but I'm pretty sure they're better for marine tanks than freshwater.

Many aquarium tubes are 10000K or even 15000K/18000K and they are ment to keep in freshwater tank. Plants grow still. It doesn't matter how many kelvin those tubes are, it's more important what kind of light they emit - most important regions in spectrum are red and blue. However full spectrum tubes are the best!

Here is a picture from chlorophyll a and b -synthesis:

(aallonpituus = wavelenght (nm))

bushy growth, but with 6700 i'd get more "height". is this true?

Red-region increse growth in length and blue-region increase growth in wide. Plants look green because they reflect green-region Carotenoids can absorbs different kind of wavelenghts.

ps... i'm looking for more horizontal, "bushy" growth more than height...

I think it's theoritically easy to do, but practically not. You can still try it...

 

[Silly me]

6500 Kelvin is not 100% correct, . In fact, the technical definition of the term "color" used above is directly based on psychophysics experiments performed with human subjects and standardized by the CIE (Commission Internationale d'Eclairage) about 60 years ago if not more

Mrv

The curve is typically double-peaked, with maxima around 420 (blue) and 670 (red) nm and a "valley" around 550 nm. The curve drops sharply below 400 nm and above 700 nm. The peaks are broad and not as pronounced as the central peak in the photopic curve. There is still significant response in the green region around 550 nm.

The standard measure that quantifies the energy available for photosynthesis is "Photosynthetic Active Radiation" (aka "Photosynthetic Available Radiation") or PAR. Contrary to the lumen measure that takes into account the human eye response, PAR is an unweighted measure. It accounts with equal weight for all the output a light source emits in the wavelength range between 400 and 700 nm. PAR also differs from the lumen in the fact that it is not a direct measure of energy. It is expressed in "number of photons per second", whose relationship with "energy per second" (power) is intermediated by the spectral curve of the light source. One cannot be directly converted into the other without the spectral curve.

 

[mrV]

6500 Kelvin is not 100% correct

What do you mean by saying "6500K is not 100% correct"?

 

[Silly me]

uhm oeps, meaning 6500K does not always mean is fullspectrum,

the color of a black media heated to 6500K will produce the same color as a florecent tube with what spectrum?? , a mix of orange green and blue?? it doesnt always contain the right blue, the right red, but a mix of green and somtimes just a spike of red and a spike of blue

 

[Silly me]

What I wanted to say was that sometimes for a tube that have all the right reds, and greens and blues, the color renderd by the tube display the same color of a black media heated to 10 000K - 18 000K

 

[mrV]

Of course, it doesn't mean - K is only colour temperature. Ra-index is also very important to know too. Full spectrum lights has Ra-index 90-99. Here is e.g. picture of spectrum of full spectrum light (Philips 965):

Copyright Samu Saurama

As you can see, the spectrum covers whole visible region.

Usually the lower the K is - the yellowish the tube is and the more higher K - the more blueish tube. But range 4000-6500 is perfect I quess. I used 6500K, because it's very white ligth - but unfortunately very "dead" too. Im thinking to try alittle bit lower K.

 

[mrV]

And e.g. here is a spectrum of Hagen PowerGlo:

Copyright Samu Saurama

 

[Silly me]

Philips full spectrum fluorescent 'TL'D/90 de Luxe 5300 K CRI > 95

PUR Total uE/s 8.9
PUR Blue uE/s 2.0
PUR Red uE/s 2.4

Sun light

PUR Total uE/s 22.8
PUR Blue uE/s 8.9
PUR Red uE/s 10.8


This is 150% correct but that all it means.

Usually the lower the K is - the yellowish the tube is and the more higher K - the more blueish tube

Both the Hagen PowerGlo and the Philips 965 claims to be full spectrum but the mix of color is not the same but both produce the same color

But the more you look into light and the color the more confuse you make everyone else..

 

[mrV]

Both the Hagen PowerGlo and the Philips 965 claims to be full spectrum but the mix of color is not the same but both produce the same color

Hagen PowerGlo is 18000K tube unlike Philips is only 6500K so you can see differences. Hagen is a little bit violet and Philips is more neutral.

I personaly like tubes between 4-6500K because they don't "bend" colours (or like manufacturers speak it like "improving") like usual aquarium tubes do. You know...

As you can see

Aquastar (Sylvania) makes sand to look a little bit reddish and it's annoying. I don't like those tubes at all - I more prefer natural colours.

But the more you look into light and the color the more confuse you make everyone else..

And sellers make more money!