Join Date: Mar 2004
Location: S.F. Bay Area, CA, USA
My ideas are unpopular, but I've found that the 12" strip light that goes on the All-Glass 2.5-gallon tanks provide sufficient light to grow a very wide variety of plants, including some very light-hungry species. The trick seems to be in finding the right bulb. The T5 that comes included in the fixture is really good - grows plants very well and the color is perfect - unobtrusive and bright. But some of the tubes I replaced it with gave me horrible results. Finally, I e-mailed All-Glass and asked what bulb was included with their fixtures, and they told me Sylvanian daylight. I finally got a hold of one (via on-line bulb supplier) and things are happy, again (well, except for the unrelated GW outbreak I've been experiencing in the tank for the past week or so). Incidentally, All-Glass has recently come out with their own line of replacement bulbs (normal-outputs as well as PC's) and they're supposed to be 8000K with very good CRI. When it comes time to replace my Sylvanian, I may try one of these.
The thing I would worry most about with overly intense lighting is algae. At one point, I bought an incandescent fixture for this tank so that I could use a 10W screw-in bulb. This was disastrous - only one side of the tank was lit, and on this side, I got serious green spot caking on my Anubias 'petit', Bacopa monnieri, driftwood and glass. I guess as long as you only have fast-growing stem plants, a bigger worry for you is having to trim every other day.
Anyway, I hope you don't end up with a 2.5-gallon algae farm. In case you might be interested, Big Al's is selling this new Coralife Aqualight which is 12" and holds TWO 18W PC bulbs. Heck, I wouldn't put something like that *near* my 2.5-gallon tank, but I'm sure people are doing it.
Just my 2-cents.
Best of luck!