Currently I am using the two 15w 18" bulbs that came with my aquarium. I realize this is insufficient but I can't afford to upgrade my lighting right now. What can I do to maximize the effectivness of my current lighting situation? Does the kelvin rating even matter with such low intensity lighting? If anybody has any tips or ideas for a cheap way to increase plant growth it would be greatly appreciated. BTW my tank is already planted with anubias, swords and hygro.