The blue lights for my pond didn't work very well. The fish, the pond liner and the algae on the liner and on the sand all strongly absorb blue light, so the visual effect was very poor; the fish just looked black and because my water is so clear, with so little suspended particulate matter, there was no scattering to make the water glow blue. Blue lights in my room make various things fluoresce slightly, but nothing in the pond responded that way.
I think I'll get one of
these and encase it with some clear aquarium silicone and bits of plastic food packaging. The amber one should do a nice job of showing off the goldfish, and I've been curious about these ultra-high output LEDs for a while now, so I'll get to see how good they really are. The red and blue ones might be fairly good for growing plants indoors, but the sprectrums aren't quite ideal, so I don't know how they'd compare watt-for-watt with horticultural T-8 fluorescents.
