Questions - Need some input

The light that came with my 55g used tank supports two 55 watt power compact whites and two 55 watt blue actinic bulbs but has an additional light bar of some kind running along the back edge that I would like help identifying. It is a thin little tube and emits a bluish lite that almost looks like a black light but probably isn't. It is also wired separately from the main lights.

The light has no labels but the guy I bought it from said it was a coravue knock-off and that he was ...

Building my 20 gal long sump from vague plans found on the internet and answered questions from here. Thanks Melev. I am about ready to plumb and saw the writing about drilling two holes in the return line to create a siphon break in case of power outage. Where exactly does that go? I thought it said about X inches below the water line but that doesn't make sense to me. Please answer and explain. Thx