um ... sorry, I think there's been a mis-understanding ... the unit is going to be about 2 to 2.5 ft above the tank ... that way I can look down into it like a 'pond' or see through underwater like an aquarium
(hence the overkill of 192 watts PC
and 128 watts T8HO) ... I might only run the pc
's for about 8 hours, leaving the t8's on for 12 ... or the other way around, leave the pc
's on for 12 hours and bring the t8's on for 8 ... that first option would help the pc
's last longer
good point about the glass and the likely hood of water splashes being minimal ...
does it make sense thinking of the glass as another 'wall' in the box?? ... I had planned on mainly using the glass to help create a 'sealed' box so that airflow could be created over the bulbs in a more controlled fashion (similar to what placing a hood ontop a glass canopy accomplishes)
upon further thought on that matter, it might still be a problem, since end of the bulb nearest the air intake will receive 'cold' air from 'outsid'e, but the other end of the bulb would receive hot air heated by the bulbs, unless I made the fans move the air fast enough that it didn't have time to heat up much ... but then that would create a whole lot of noise!
I wonder if it's really nessecary ... I would like to keep these bulbs a little on the cooler side (under 150°F?), to get a bit longer life out of them, but at the same time, not cause cold spots by cooling one part of the bulb more than other parts
heh, at my old job before going solo, we had a mechanical engineering department with many people that loved thermodynamics ... they coulda told be the best way to acheive even cooling with minmal noise
may just routing some slots into the aluminum reflector and putting a single fan above the reflector directed out the top of the hood would provide enought 'up-draft' cooling to slightly cool the bulbs, without the need for a large (and heavy) piece of glass
my plan on moving the hood out of the way for major surgery and such would be a pair of double ended clips, I'd just clip one link on each chain to a higher link, shortening the chain and getting the contraption out of the way ... sounds resonable enough?
keep the feedback comin, please