I have an Aqualight Pro fixture w/ 1 250w mh bulb and pc's. My question is how far up should the fixture be above the water? Its currently sitting 4.5-5 inches above. I have some sps (acros, sunet monti, red chilli pepper) acclimating on the sand bed and im worried that when I move them higher up in the tank it may be too much...will this would be a problem?

I would keep it ~10" from the surface of the water. IMO, a 250 is perfect for your tank if you're keeping SPS. Good choice!

Thanks. Follow up question though...I currently have the stock DE 10k mh bulb but I want to switch it out to a DE Pheonix 14k, IYO do I need to acclimate the coral again after the fixture move and change of bulb or is it not as critical?

usually if you go with a higher kelvin light acclimation isn't that big of a deal. I would suggest since you are overpowering the tank go with a 20k. If you read my tank thread you are at a higher W/gal than I am. The 20k will provide you with much better color and because you are overdoing the lighting you will not have to worry about the loss of growth. If you are going to go with a 14k go with pheonix IMO it is about the same as a 20k

I would defineatly raise the light to about 12" off the surface. You might also want to run a fan over the water off the same timer you'd be using on your light. I think I went over this in the begining of my thread for my AP24. You can check it out in my sig if you want to get a better idea of what I'm talking about. A 20k bulb will also make your coral pop a little better with little or no effect towards growth rate.

Why a foot off the water, you will waste half the light with spillage. I have a 400 over a 58 and a 250 plus Pcs over my 40b frag tank. You will be fine at 6 inches this is the distance from water to glass on all my lights. 12" might be OK for acclimation but really it will light the whole room. Dont trust me try it.

I'm running a 150w with 2 24" t5's along with 2 36" t5's over a 40br and I harldy ever kick on the 24's just because their not needed. A 400w is a little excessive when your tank is only 16 or 18" deep. Temp fluctation is a big deal when your getting into more powerful halides and sps are some of the first thigns to go when things get too hot or too cold too rapidly.

my tank goes from 80.1 to a whopping 80.9 sometimes it gets to 81. Fans and a sump are as good as a chiller. I buy wild acropora and attempt to color it up. SPS are hardier than most think especially when they are truly healthy and well fed. If you cant see your acros swell up, I mean literally inflate, you should feed them. If anyones levels for Phos and nitrates were actually 0 they would have 0 coral growing in there tank. Many people argue me over my posts, the simple fact is this is an easy hobby as long as you keep up with WC and give the coral plenty of light. Run the halide 12" from the tank record the temp swings, then for 2 days put it as close as you can get it without getting it wet. Pleas record and do put a small fan blowing over the tank. If you go with 20k you will not need any actinic unless you REALLY like the blue. I encourage you to take NO advice, try it for yourself and post the results or just pm them to gulf surfer and me.

You just gotta find what is best for your tank. does the temp fluctaute too much, is there too much evaporation, how to get an ato to work with an all in one, do you want to run a sump and all and all what is pleasing to you. For me I just ended up tearing out the false wall on mine and throwing a ten gallon sump and massive skimmer under my tank and stuck the biggest light I could find over it and all worked out pretty darn good. Good luck to you buddy, hope you get things rolling in the right direction.