Re: My 30g... - I have 175w on mine but I would rather have either 2x 250w DE's w/ dual T5 actinincs or just 4-6 T5's.. - Preferrably 4-6 T5's with 3/4's of them actinic.
Wow, I really think that's overkill. Much simpler and cheaper to just buy a single MH bulb and leave it at that. A 250W MH bulb of any Kelvin rating 6500K-20000K will be suitable for the majority of corals.