Mh Bulbs

Ok guys im upgrading to mh lighting and was wondering what you guys think of these bulbs i found. they say they are for aquariums but they are onyl 12.86!! anyhow heres the link let me know what you think http://www.1000bulbs.com/250-Watt-Me…quarium-Lamps/ thinking of going with the 14k...

distance between light and water surface

i am making my custom lights, i am just wondering whats the ideal distance between the tubes and the water surface. my current distance is 8 inches. i am just wondering water vapour might damage the tubes. my tubes will not have any cover on them so what you guys think?? distance between light and water...