I was given (2) 400w metal halide pendants with the controller box. They each have a Hamilton double ended 14k bulb that are blown, however I have seen them both working in the past and know where to buy replacement bulbs. I have used a wide variety of LEDs and T5s but have limited experience with MH (I am aware of the heat implications, the cost of bulbs, and the need to change the bulbs every 12-18 months). What are my options? What depth of tank would I be able to use this with and be successful at raising corals? Would one or both lights be too much for a 55g? 75g? 120g? 150g? What type of corals would appreciate this much light? If this is a viable option, should I purchase the 10k, 14k, or 20k bulbs? Thank you in advance for the helpful input!