I meant using exotic wavelengths that are not normally used produces really weird coloration. Not like getting the red leaves redder or someting like that. Just very weird colors you don't normally see.
And because the aquascaping hobby apparently is not an enemy to unnatural looks one can use weird colored plants to create some kind of unseen alien scape.
The grow light that I used yesterday indeed created very ugly shadows around the plants - purplish red, very unnatural and tastless looking.
The absorbtion of wavelengths by the water is a funky topic. Someone just told me that Amano believes that intensity is more important than specific wavelengths. One simple example is "white" light. It has all kinds of wavelengths and not all of them matching the photosynthetic curves perfectly. But if I think a white light will grow plants worst that a jacked up LED with all kinds of wavelengths I think I need a shot of reality. There probably will be a difference. But how big? What is really the point of a light engineered to surpass white light by say 5 or 10 or 20%? In another post I said that this all has to do more with one's ego than anything else. LED is cool right now, you know.