Thw blue light in a fresh planet aquarium, does nothing other than make fish
with deep colors look more vibrant, mind you if you over light your tank,
even with blue light, algae loves to grow
"John Sankey" wrote in message
...
See http://sankey.ws/plantlumen.html

Marine animals absolutely need lots of blue (actinic) but an
excess is of no use at all for fresh water plants. Mind you
I haven't looked to see if they are of any use for fish, snails
or other animals in freshwater aquaria - they might be.

As long as you stick to conventional fluorescents, the so-called
colour temperature of the lamp makes very little difference to
the way plants grow - picking what you want to look at is fine
as far as I can tell.