You should find otu how powerful your ballasts are. If you have 4X65W then you may verywell have two 110W ballasts. This would only permit the use of 2 96W bulbs. In addition you would have to match the endpin configuration.
The best bet is to replace the bubls with like wattage. Going higher could cause the bulbs to not fire, not work at peak efficency or cause the ballasts to run hotter than normal and risk fire.
__________________ Remember dont tap the glass, your fish will think you're an idiot-Anonymous mother