Interesting. And almost certainly correct - I figured there was a loss
from the shape but didn't think it might be as significant as you
suggest. I think I will continue with the test for now just to see what
happens. I don't think I'm going to change to tube lighting - mostly
because I'm only growing low to mid light plants in this tank anyway
but I may start thinking about ways to modify my current setup to get
more of the light into the tank. Deffinately something to put some
thought into.

-Daniel