i've always kept mine as close to the water surface as possible-usually 2-4" between the outer bulb envelope, and the water surface
higher wattage bulbs may require more (i was usin 175 watters), since they may be more susceptible to 'exploding' if hit w/a drop of water,given the hotter temp of the bulbs
the likely hood of a splash from a fish in my tank reaching 12 inches is abysmally small. The biggest fish in my tank will be a Pearlyscale butterfly fish.
The only concern is keeping the water off the bulb right?
a question: using a high wattage bulb farther away from the surface of the water kind of defeats the reasoning of a higher wattage bulb to begin with, doesn't it? (inverse square law, and all that)
heh-i used actinic supplements for the 1st 6 mo. after settin up me first tank after movin back to the states in '95
since then, i've never used any other light other than halide, and have found them lacking in nothing at all, from tank's inhabitants, or my own aesthetic, perspective
Hey knucklehead - just curious what make of bowfront tank? Are you building the canopy yourself? I am moving my 58 gallon rectangular tank to the basement and want to go to a bowfront in the family room - its a better fit in the room.
i will have my 175W MH's manana...i think im gonna go 12 above..gonna start out 24 and inch its way down day by day..3in above water seems like it will get hot..i have no chiller and i cant justify spending several hundred bucks to cool my 20...fortunately for me i will have the blessing of being able to readjust since it will be suspended.....my $.03...btw..what the heck is that avatar knucklehead...you gotta go back to the pic of you...that was so funny to me....