lighting questions

[Ruth]

I think you have to figure out what kind of corals you want to keep. Like reeferaddict said, you will lose quite a bit of your light value if it is over a centre brace. That being said a 400W puts out a lot of light. I have 3 X 400W over my tank (with a center brace). I still keep some SPS under the middle light but mostly digi and lesser light loving - the others are LPS and softies. I don't keep any of my clams under the center light. So basically it is up to you to decide what you want to keep. Also remember that you are going to be paying for electricty to run a 400W bulb that you may not be getting the full benefit of - your also going to have more heat output.