If youur looking at Data from 5 years ago this is correct but just in the last year LEd's have come a long way. The quality LED manifactrers are reaching 120 LUMs per watt on regular bases now for almost a year now. They are also projecting that the next generation which should be out mid this year could be exceeding 200 Lums per Watt.dono where T2 fits
T5HO vs LED, where lumens rates, ...
T5HO beat LED arrays of the same size in watts per lumen. (what people see)
unfortunately this doesn't mean anything with PAR or PUR (what the plants use)
On my reef tanks I run roughly 1/2 the wattage of LED light that I do with HOT-5's and my results are very simular to slightly better growth and much better color with the LED's.
You are correct in this aspect however you are overly simplifing it. What the eye sees is reflective light off the object that gives it its color. If the surface of an object reflects light at say 500 nm and there is light hitting the object at 500nm it has no light to reflect back at us. You can create a white light with 3 LED's peaking at 470nm, 550nm and 640 nm that will look white to you reflected off a white peice of material but if there is an object that only reflects cyan light at 500nm it will look black to you since it has received no light it can reflect back at you.Matav.
for Flouresent lights and their color spikes, ... the visible light part of the electromagnetic spectrum includes red, orange, yellow, green, blue, indigo, violet (ROYGBIV), the human eye i think really makes all it's colors based off red, green, blue, being more sensitive towards the green/yellow.
we see orange just fine, based on how much red & how much green and the brain interprets the rest. (i'm going by really really old memory, so it might be beyond fuzzy)
as for "white" light, ... it appears white for the same reason, ... the balance of everything, a generally balanced whole, but it's a balance. if the reds and the blues are heightened or diminished equally things will still appear "white" to us. just dimmer.
it's like scales, if the right and the left aren't balanced it tends to shift one way or the other
spikes are somewhere between intentional by design and intentional for marketing.
plants don't make much use of green, but our eyes do, and without that spike it's going to look dark to us regardless of the benefits to the plants, and marketing is scared of loosing sales.
Yes there is some truth to this. Very little light is utilized in the green spectrum for photosynthesis. Most of the green light is not absorbed by the plants but is reflected back at us which is why many plants look green to us. You could create a light source especially with LED's that has peaks just at the wave lengths that are utilized by photosynthesis and be able to get in thory a light that is extremely efficient. You could even individual tune this light for a specific plant only creating light that it absorbs for photosynthesis.for google searches on light spectrums of various bulbs, (5500K and higher) they can nail the blues, and the spikes the plants crave. the reds the plants want, ... it seems like they're all shifted, slightly towards yellow/orange.
a google search for a 6500K bulb
this has a balanced spectrum, but i notice the sides tend to be a little less than the middle. for everything i've read, this would give a good balance and be very bright, ... well bright to us, the reds & blues as they've taken a hit, and as these are the wavelenths the plants crave more, ... it's a good bang for your buck if you want to light a room, but for your plants, ... your money could be spent better elsewhere
However if your not giving it any light that it is not absorbing then it has no light that it can reflect back at us. How do you think the human eye would see this plant? It would appear black or near black with only the excess light it could not absorb reflecting back at us.
I say this in theory as most plants also have a low level of florescence in them. You can see this florescence in corals where you might light a reef tank with light at 455nm and the result might be a bright red coral standing out as it absorbs the 455nm light and emits 660nm light. Many fresh water plants also do this but to an extremely less extent.
The bases of goo reef lighting is to provide enough blue light 400nm to 500nm to make the corals grow than add enough full spectrum light to make the observers eye happy. For fresh water plants it is simular only the red and the blue light are important.
When I was heavy into planted aquariums I found that the best combination of lighting was a combination of Chroma 50, 5,000K lights and Daylight 6,500K lights. I had truied lower K rated bulbs but found with them it was nearly impossible to keep algea under control because of abundance of red light.