How much is too much?

[reeferdoc]

I have a 120gal AGA RR tank which is 24 inches deep and has a canopy which sits about ten inches from the water surface (so about 30ish inches from lighting to tank floor). I am getting PC and MH combination lighting. I have ordered a 400W setup. Many people have mentioned 250W should be plenty but my lfs is only charging me $80 more for the 400W system. Is there any problems with excess lights or is it always just beneficial?

Thanks! :lol:

 

[Will C1]

just be carefull you dont burn any thing, i would make sure the softer or more sensitive stuff is near the bottom, but all in all it should be fine and i would spent the extra $80 also.