Would it be appropriate for a 55?
http://milwaukee.craigslist.org/for/1347641461.html
text :
used 48" HQI fixture from Outer Orbit, see below for the lights that are a part of the fixture. Its a all in one fixture, no remote ballasts. One of the fluorescent lights is burned out.
* Complete 24-hour lighting - 10,000k HQI metal halide, Dual Actinic Sunpaqs fluorescents & Led Lunar Lights
* Microprocessor based driving system - 15% more output
* All-in-one fixture - industries first integrated electronic ballast (no remote ballast’s)
* Cool running, ultra-quiet fans for maximum thermal efficiency
* Easy installation - stainless suspension system and docking mounts included
model no.1042 2 x 150 watt Hqi 2 x 130 watt fluorescents Led Lunar Lights size 48" x 15" x 4.25"