I will tell you what I did and had some level of success with. I didnt want to buy the regular
T5 lights because it was so expensive to get a 5 or 6 light fixture and then the reef bulbs for it were an additional $20-30 at my
LFS (over priced and under serviced). I decide on a
MH. You might be thinking thats way more expensive! Not so unless you want coral life or some brand name bull...What I purchased was a 400w
MH grow light. It came with a new M59 balast, decent reflector, cords, a 6000k bulb, everything you need but the chain to hang it(no assembly required). I have since moved to a 14k bulb to cut down on alge growth, however the corals, hard and soft alike grew like crazy (under 6k they dont get the color but boy do they grow. Several coral propagaters I know use 6k to grow and then 10-20k to color them up before sale) That also may be due to the fact that I have almost 9watts per gallon. I also got the 14k bulbs off ebay for about $20 each, from different sellers...one bulb was great the other was dead within a month. The good seller was, greatdel. The light was purchased for i believe $119 (all new parts) from HTGsupply on ebay. I think they probably supply mostly closet pot growing opperations but I recieved a great light reguardless. From experience keep a spare bulb on hand! I lost like 10 sps
frags because I lost my
MH light and had nothing else to keep them living...All the
LFS wanted $100-150 for a bulb and I couldnt do it at the time. So I ordered off ebay and waited a week...2 of my
frags have actually started to come back , i was amazed! Lesson learned, I keep a spare bulb around now. If you go with a
MH light dont get a 400w unless you plan on upgrading to a large tank in the future as 400w is far to much for my 46g or your 55. A 250w would probably work just fine...I
bleached some
frags (which came back till my light died) because I was told they were very light hungry and put them in the top third of the tank,
bleaching them white in 2-3 days. I since discovered corals cant be in the top 1/3 of the tank, they did well...I kept several in the sand bed even. The light is obviousy to powerful
lol. But I am switching to a 190g all glass and have purchased another 400w
MH...good luck