Lighting Question

[Arbee03]

Hi,

I hope someone can help me out with this one. I picked up a used 48" PC lighting system (no markings or writing to determine the brand name) that came with 2 Daylights and 2 Actinic bulbs. My problem is that the bulbs are only 12" long, so there is quite a gap between each side. The daylights say 36w on it but nothing on the actinics. My question is do 48" PC lighting fixtures usually come standard with 36w bulbs or can I use higher wattage pc bulbs? I checked the ballasts and there were no indications on max watts allowed. I noticed that most power compact fixtures were being sold with 4X55w, 4X65w, and 4X96 watts but nothing at 4X36w.