I emailed Marineland to get the specs of my common 15 watt 18" T8 "Eclipse Natural Light" bulb. These come standard in a lot of dual hood 55g set-ups, such as the Top-Fin 55g combo one they sell everywhere. Here they are:
By comparison, here are the coral-life 50/50 bulbs I ordered:
Since this info is for just one of the two bulbs in the set-up, I'm expecting a pretty good increase in light. Hope this helps someone. BTW
, can someone let me know what CRI is?