Actinic 03 Lighting and Planted Aquaria

Michael Taylor asked:

>Hello all. I was recently having a discussion with a fellow plant keeper
>who stated that they supplement heavily with actinic 03 lighting on their
>plant tank. I have often pondered this, but couldn't really see where the
>benefit would be. I would like to hear some ideas on if/how/why this is
>or is not effective. I am sure that it will be of benefit to all of us.

It has been my experience, and that of several friends as well, that
actinic lighting over freshwater planted aquaria tends to proliferate the
growth of green algaes. Though there is no documentation of this that we
have seen, we have all seen it over and over in meticulously maintained,
low-phosphate, highly lit tanks that are virtually algae free with lighting
in the 5000 K neighborhood. We have even seen this true to a smaller degree
under Triton, and 6700 K Ultra Daylight PowerCompact bulbs as well (Tritons
have both a higher blue output and ensuing Kelvin rating: around 6500 K if
I remember right).

Also, to my eye, actinic lighting tends to make a nice planted tank look
very much on the "eerie" side; with greens getting very garish and lovely
red plants (R. macrandra) getting a little washed out. I think bulbs with a
Kelvin rating closer to 5000 K is much more natural looking to the eye.

I must point out that in recent years most of us have acknowledged that
plants can utilize most of the spectrum--blue, red or green--so they do
grow fine under actinic light.



Todd March
tmarch at primenet_com
Northridge, CA