That 54w should be interchangeable with any standard 54 watt bulb. I believe some companies measure from bulb end to end and some include the pins in their measurement.
For instance, wavepoint sells a 33" bulb but its for a 36" fixture. I was baffled at first myself but after ordering the "short" bulb it fit perfectly anyways. lol
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.