Good efforts on trying to find ways to use LEDs
Im wondering how much light is wasted and not used for photosynthisis
Quite a bit.
The 3 watts alone are really really bright and im wondering if we really need to use that much lumens considering we will be lighting up a very small area and not a room or spot of a large area.
I looked at the ones you linked to; says equivalent to 20 or so watt bulbs. If that is incandescent, then it's way to small. But my knowlege is limited here.
1000-3000 Lumens for LEDs is just insane and so out of this world pricey
Some folks on another thread found 1000 lumen for $100 or so. I think. But you do need high output.
Here's a thought... any reason the screen could not be submerged in a sump?
No... won't grow. Must be a thin film of flowing or splashing water.
Why don't you just do a simple experiment with what you have? Not full size. Just use a plasic bowl, and some air line tubing for the water flow pipe (slit it lengthwise). Use a tiny nano pump, and one of those small LEDs. If you can fill up the screen with algae in a week, two weeks max, then you know if you up-size it to aquarium size, it will work.
without creating more water flushing noise
When built properly, the waterfall is silent.
I'm thinking just stick a large lamp in the sump and let the algae grow on the available surfaces. One could just scrape off the unwanted growth when doing water changes.
You can do this as an experiment, but you can't clean in-system on a regular basis. You need a screen that you can remove and take to the sink to clean; otherwise your water will start yellowing.
Here is the one LED design so far; This one is from "snailrider" on the AC site:
And this info is from "oceanus" on the SGRC site, edited slightly for readability:
"Not all LEDs light will work on plant culturing. Some LEDs may seem to be very bright in the eyes, but they lack the wavelengths needed for plant photosynthesis. Here is a extract from Photo Morphogenesis in Plant by R.E. Kendrick and G.H.M. Kronenberg (Published in 1986, Martinus:
Relation between WAVELENGTHS and PLANT CULTIVATION:
1) Plant photosynthesis occurs at a wavelength of 400 nm to 700 nm.
2) Certain wavelengths have greater influence on photosynthesis, 400 to 525 nm (blue color)
and 610 to 720 nm (red color) are the biggest contributors to photosynthesis.
3) Wavelength between 520 to 610 nm (green color) has the lowest ratio in plant pigment
absorption
In regards to the principles stated above, organic lighting that is sold in the market usually refers to two specific wavelengths, the red and blue wavelength. From a distance, the color of this light is pink in color.
As for white LEDs, most of these utilize a blue color chip with a coating of yellow phosphor; with this combination, white light is the end result. Therefore, the energy distribution of this white light has two distinct peaks at 445 nm (blue color) and 550 nm (yellowish-green color), but organic life also needs wavelengths at 610 to 720 nm (red color), and white light lacks this wavelength. This is the reason why white LEDs are not advantageous for organic life cultivation."
