2 watts per gallon is a good rule of thumb, depending on what you're putting in
it. If you are using low-light plants like java fern, 20-25 wats would likely be
ok. Now if you have high-light plants (like cabomba) you should have 40+ watts.

--
Billy
ABSURDITY: A statement or belief manifestly inconsistent with one's own opinion.
"I know of no time which is lost more thoroughly than that devoted
to arguing on matters of fact with a disputant who has no facts,
but only strong convictions." (James E. Thorold Rogers)
"Zerex" wrote in message
...
: I have a 20-gallon TALL tank that I am going to plant. I plan on getting a
: light kit from AH Supply, but I'm not sure what I should get to light this
: tank. I know I'm gonna need a lot of light since the tank is so deep, but
: beyond that, I'm clueless as to how much light I'll need. Any suggestions?
:
: thanks in advance,
: jim