Other than using fresh bulbs (GE Deluxe white mixed with a GE "plant and aquarium" bulb for better spectrum coverage from home depot are my choice) i use a splash of flourish once or twice a week. Though if you're using plants that feed mainly from roots, a root tab or two for each wouldn't be a bad idea. I'm using four 4' t8 bulbs on a 180 gallon, and only put plants in the middle section where they overlap. Seems to be doing well for me.
Much easier than my old high tech setup with CO2, PH regulator, daily dry ferts, blah blah blah.