i have a 30g tank. right now i have one 65w pc. i want to be able to put any kind of coral or invert i want in this tank. can i go with a single 175w mh or 4 vho, or 1 mh and two vho. need some serious input here. also what exactly is the difference between the 175 corallife bulb and the 175 watt sylvania bulb i can get at lowes for a third of the cost.