ok so i have a 90 gallon tank, and i decided to upgrade the NO fl lights to metal halides. i bought a 458 watt 49" fixture, and just put it in place of the other light fixture. bad idea. cracked both glass canopy tops. now comes to my question . . . how far off the water should these be placed? there are 2 175 W MH
's and 2 54 W T-5's. also, should i plan on replacing the glass or can i just leave it open on the top of the water? i do have a canopy that i built that i will now have to modify since the light is 1" too long, but that is the least of my worries. also should i "break the tank in" to the lighting? and will i need to do anything to dissipate the heat? not a bad price that i paid though. $360 delivered from ebay. its a Jebo 2007 458 watt MH
with moonlight clusters. Any help would be appreciated. Thanks. BTW, the tank has been up and running for about 12 months.