Marie,
I use 2 spot lights from CanadianTire ($8.99/ea) & 2 Phillips Daylight CFL bulbs (23 or 26w). These are clip on lights attached to adjacent bookshelves.
Here's the top of the Hex tank with 2 spot lights on Irene's Taro plant & the Lucky Bamboo.
The Taro plant has grown 2 new large leaves in less than a week since going in the tank. Must like living indoors after 4 months outside.
Anthony