Quote:
Originally Posted by jtma508
Reds penetrate to 15m ( http://www.waterencyclopedia.com/La-...the-Ocean.html) and when you consider the DLI found in nature relative to our best setups (which provide less than half) this susumption may not be true.
On the second point, if you look at the spectra of either T5 or MH you'll consistently see the same spectral peaks. |
If you read the paragraph before that quoting 15m, you will see that 25% of all light is gone at 10m. For our eyes, the red spectrum is gone at 10 feet, which is about 3m. I was being generous with 5m. Yes, some long waves penetrate, but these waves are simply so quickly reduced, they really don't play a role anymore. Google some articles on underwater photography. You will get more of a feel of what is spectrally happening.
As to bulbs showing a spectrum with red peaks in their specs., my eyes cannot confirm this on comparisons with bulbs listed at the same spectrum. I really don't trust the reported spectrums. Certainly some are correct, but others are clearly not. Still, in my tank, which is 70cm deep, there is very little red left when the light hits the bottom in any case. Or I can't see it. Red corals placed at the bottom are no longer bright red in my tank. At about 12" from the HQI, they are red, 28" away and they are quite a bit 'browner', for lack of a better word. Some greens as well get much bluer, almost dark turquoise on the bottom, while yellows get greyish-green. Fluorescence or lack there of are playing a role, here.
Whatever is happening, I am convinced that the red spectrum is not playing a big role, except for the aesthetic side for some. As an artist, I consider myself very colour concious, which influences much of my perception. I guess we will have to wait and see, if the corals react differently over the years with less red under the LEDs.