With my tank I received a light that has a 20w bulb. Is it possible to purchase a higher wattage bulb for the fixture, or do I have to purchase a whole new one? I eventually want to make my own canopy and put in a 96w bright kit from http://www.ahsupply.com, so I'm looking for a short term solution to make the plants I have happier. Any information would be great. Thanks!