Not too much I could recommend, if you're risky you can try to wash off some of the outside soil from the rootball and plant it in some fresh soil with lots of perlite(about 30-50% by volume). Also adding a fan blowing across the top of the soil should help dry it out and prevent mold from it being constantly wet.

Also your light is just fine, not ideal but if you keep the plant small it should be good. I've got a 200w CFL myself and it's doing wonderfully with 12,000 lumens on a 2x1 space. I hate people always trying to recommend expensive HID when you're obviously on a budget. If you want more light I'd say get a few clamp lamps and some 23-42w CFL bulbs from Home Depot for additional side lighting. Should be $20 or so for each new light & fixture.