Not so much the wattage but the intensity. Wattage plays into it since it has much to do with that intensity, but it is not the single determining factor.
Most importantly is how that intensity gets diffused and dispursed through water for our photo friendly tank stock. Different delivery methods are affected differently by for having to force the light through water.
T5 IS better than PC for sure. But reflectors, bulb brand and your own tanks layout all play into what is the best choice.
Personally if given the choice between 130w PC and 48w T5? I would stick to the PCs.
Bumping it to double numbers, or 96w T5 vrs same 130w PC, then hands down I would go with the T5.
I always ramble.. but I put much more personal stock in upkeep and maint than I do about pure HP equivilancy rating for fixture/bulb combinations. Those of you know who you are with the saltcreep out of control. The stained reflectors and swap meet bulbs. Its always easy to blame the method rather than yourself for keeping the reflectors clean and bulbs of good quality and within lifespan over our tanks. So much more to it than just blanketing oranges against apples if the playing fields arent leveled with proper care and routine upkeep of any equipment.
Not accusing or implying you dont already keep a clean ship, but it is just as important as anything else in your system.
Hope that makes sense.
