I feel dumb for I had thought for long the effect was opposite. I guess taking my results for correct, I didn't really pay attention to books and texts stating it just opposite, a perception/attention 'flaw' of the mind, but that is psychology, and still, my shameful mistake.
I stated also a misfitting description for the plants in red light. They wasn't actually compact
, but thicker or denser. The rosette had a shorter span, but because of the shorter peduncles, shorter than in the ones in blue light. Can't explain that, but it was so. It seemed a coherent conclusion to me. We used regular coloured incandescent bulbs, and had no idea of the spectra, and the sampling species was (I know now, thanks 2la) not suitable for the experiment--I was in junior high, and about 13.
Unless your tank is two feet deep or deeper, the attenuation of red light with depth isn't all that pronounced--even less so given that most people keep their (background) plants not much more than six inches or so away from the lighting fixtures. (Bear in mind, also, that sword plants aren't stem plants with internodes, making the effect of photomorphogenesis--or antiphotomorphogenesis, as the case may be--difficult to validate...)
I didn't mean the attenuation was in our tanks, but in the wild. I suppose a plant that would be three feet or deeper underwater, would try to reach up for red light. However, due to the low depth of our tanks, if a lighting fixture lacks enough emissions of the red portion, it will be almost all the same in point of depth. I think the plant could "feel" like it is too deep for it, and then try to reach up, but never finding the spot. Although that would mean that eventually it would come out of water, which I can't explain, rebate or confirm.
I agree completely with bad choice of plants for the experiment.
It would take me a lot of proper
experimentation to prove if some principles/phenomenons work differently for water plants.
Thanks for corrections to my lousy