metal halides are hot!

[mwrmma]

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.

 

[melosu58]

I would leave the glass tops off as they will cause low PH due to poor gas exchange. Your info does not give any so I dont know what type tank you have. If you have corals then yes you`ll have to break your tank in. Starting off at maybe a couple hrs a day and moving slowly up as the days go on. I dont use a canopy on my tank but if you want yours ,like you said you`ll have to modify. Good Luck

 

[mwrmma]

so is 8 to 10 inches off the water surface enough space? also, does anyone know where to buy those little 4" cube fans?

 

[melosu58]

I think most people use those computer fans but I saw some advertised at Smith and Foster. Liveaquaria .com