In lighting a 20g long, I've got a choice between a two bulb
florescent strip (total 40 watts) and a Smartlite CF fixture (65 watts
with a 50/50 10,000K/actinic). Which delivers the most beneficial
light for growing freshwater plants?

If you go the Custom Sealife route, don't get the Smartlite. Get the Britelite
instead. The Britelite is better for planted tanks than the 50% actinic
Smartlite.

As for which is better...the Britelite will provide more light. So much that
CO2 injection will be mandatory, not optional.

Two 40w bulbs would be much cheaper, and would probably provide enough light
for you to grow most plants, since a 20 gallon long is only a foot deep.


Leigh

http://www.fortunecity.com/lavender/halloween/881/