Something that always confused me is why they sell plant bulbs that fit right into the hood, but are only around 20 watts for a 30 gallon tank. barely over half a watt per gallon, will this bulb maintain simple plants, like java's, bunch plants like wisteria, anacharis, so on? This is for my older sister, who isn't willing to spend very much to change the lighting on their basic 30 gallon with a hood. They want plants, and I've always thought those bulbs don'y really work well. Any suggestions or experience with this?