confused and need help

OK, i am new to this forum and happy to hear anybody's input.
basically, i have been researching par and kelvin lumen etc... and have run into a lot of questions.
first, it is widely accepted that the best light for coral growth is around 6500k and the best for appearance (but no growth) is around 20000k with a happy median being around 10000 or 12000k depending on individual preference. these bulbs are usually supplemented with actinic lighting like 420, 460nm... in order to reproduce the spikes in the PAR graph. everyone generally agrees with that statement right?
here is where i start to ask questions...
if you have a light 10k/460nm then your ultimate light output is going to be at a much higher kelvin rating then just an original 10k light. i have read that 460nm is basically 50000k. so, your ultimate light output or average kelvin rating would be at like 30000k and that's said to be way out of range for any coral growth. but that's obviously not true.
is it that the 10k provides the necessary other parts of the spectrum like red, orange etc... and the corals use what they can from what you provide?
if thats true then why doesn't someone find out where the other spikes in the PAR graph are, then figure out what the percentage/ratio of all the usable colors is and build a light (a "PAR light" if you will) that will have like 1% 510nm green, 1% 590 yellow, 15% 610nm orange, 20% 670nm red, 25% 420nm blue, 38% 460nm blue (something like that). that would (in theory) be the perfect light or the "PARfect light". right? OR...... did i just list the light composition of a 6500k bulb and talk in a big circle. idk
either way i am confused.

 

I would go with a mix of color temperatures to achieve what you want.

I personally run a mix of 10,000 kelvin and 460/420nm lights above my tank with great success..

 

Oh, and welcome to 3Reef!

 

Ya, thanks. personally, i have a custom 192 watt 64 LED unit with 10k, 6500k, 420nm, and 460nm 1:1:1:1 ratio. I'm just intrigued about this topic and looking for input.

 

Although I dont yet know much about LED, I do know enough about lighting to know that your combination of temps will produce some good growth. I do believe that 6700k is the best growth color, but for me I think it makes my display look yellowish. I run all T5-ho lighting but hope to get into LED as they are more developed and the costs come down a little bit.

 

I was worried that the 6500k light would be too "yellowish" that's why I put them together with 10k's. However, LED lights are alot "crisper" and the 6500k bulbs actually look really good. (The only way i can tell the difference between the 6500k and 10k bulbs is by wearing polarized glasses and looking at them).

 

put up some pics of your light setup for us to see.. I am really curious about LED..

 

IMO, there is not such thing as a perfect spectrum as different corals need different wavelengths and different intensities of light. If you have a 10k and an Actinic bulb, the overall kelvin color would be more blue, to my knowledge, it doesn't negate the spectrum the 10k puts out. You still have the fuller spectrum from the 10K with a large blue end from the actnic, so you should still get growth and color. However, there seems to be a focus on color in corals, that's what sells for vendors. Most vendors don't aquaculture, or at least don't purely aquaculture, so they really don't care about growth rates. They want great color. Thus, there doesn't seem to be a huge demand for lower K bulbs and a perfect PAR bulb would most likely be a much lower kelvin rating. Also remember that corals can only use so much like, if you have really high PAR levels, that doesn't mean your corals will grow super fast, I believe the use to growth would fall on a parabolic curve with an ideal ratio of PAR to growth, but that doesn't factor in the aesthetics or personal taste.

 

like it

 

Could not have said it any better...

Using 20k Radiums with 24w of 420nm HO LED's as supplemental, coral growth rates have been wonderful and the color is heaven!