I've been doing some research and a lot of people are saying that the watts
per gallon (wpg) rules for adequate lighting are becoming useless because of
the newer T-8 slim flourescents compared to the older T-12s.

In fact, one person said that with a light meter they found out that 4 T-8
bulbs put out nearly twice the light of 4 T-12 bulbs! Some people are saying
that the quality of light is better: they can produce a broader spectrum of
light.

SO! Do I actually have good enough lighting with 2wpg as T-8 bulbs?? I
currently have 1 LifeGlo 15W and 1 PowerGlo 15W for my 15 gal. (most people
say that 3wpg is more the idea lighting).

And the bonus, T8 is more efficient (run at less current but higher voltage
then the T12), puts out less heat, degrades light intensity slowly over time
and to a lesser extent.

Any opinions?