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Re: [APD] 10,000K CF

S. Hieber wrote:
> The energies directly corelate with wavelength. Plants care somewhat, prefering red and blue more than green.
> Bulbs what diff color temps will have diff mixes of phosphors and can have diff efficiencies for light output relative to energy input.  However, one would be hard pressed to find a general corelation  between bulbs of diff color temps and efficiency.
> The infra red photons are the least useful for growing purposes -- unless your plants really need the heat, which is not usaully the case. The intitial output in a fluorescent lamp is of a large quantity of UV photons. It's these UV photons striking the phosphors that knock some of the electrons up a shell, from which unstable state the electrons collapse back to the normal "orbit", releasing lower energy photons in the process. A lot of factors can be involved in the efficiency of this process. It's not just techonological diffs, if by that you mean the fundamental design type. Bulbs of the same basic design can vary in terms of the electrical resitance of the filaments, the quality of the filament coating, the quality of the phosphor coating, the gas, etc. Even within the same run on the same line, individual bulbs will vary somewhat -- and certianly there are variances from brand to brand. 

I was thinking more along the lines of "if you send X watts of energy 
into the mercury vapor, you're going to get Y photons out." That's 
physics and will always be true. Then, the technological differences 
being the quality of the filaments, phosphors, etc. That's the only 
place for there to be any significant difference. I suspect, but have no 
proof, that the PPFD efficiency of various bulbs is more strongly 
correlated with its color than its brand or type. In other words, I'm 
suspicious that bulbs emit roughly equal amounts of energies per 
input-watt, but their spectral variation accounts for the differences in 

"He who throws dirt is sure to lose ground."

Jerry Baker
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Aquatic-Plants at actwin_com