Steve,

You don't need to go with a 400watt metal halide. I must admit I went a little over board when I bought my lighting, but you know I should be able to grow anything expect low light stuff hehe. My love though is for acropora's not low light stuff. With a 250w you will be at 7.5 wpg, which ain't bad at all dude. I am going to be running close to 20 wpg. That is almost insane, but you know still ain't as bright as the sun. :lol: I don't think you can go wrong with a 250w. I wouldn't be trying to push a 250w bulb though off a 400watt ballast, you would almost me begging for trouble, as I am told most ballast don't go backwards, but some do. You know though if you are going to run a 250watt bulb, buy a 250watt ballast. From what I can tell from what you wrote about saying you are more worried about coloring then speed of growth I probably wouldn't even think about a 10K. I was running a 10k which was bright, but the acropora's turned brown, and now that I am running a 20K the color is finally coming back in them... Thank god. This is just my own personal observation though. I think you can be set up with bulb though for under 300... Or atleast I would hope you can.