browncj7":3pc80zyf said:
Are you currently chilling your water?
MH generate much more heat than PC and you will need to chill the water.
This is a common misconception IMO.
The equivalent wattage of MH may produce slightly more total heat than PC, but it also produces a
lot more light. If you compared them in configurations where you had equvialent
light output, the MH is actually producing less heat (more efficient light source, so less power is consumed/wasted to produce the same amount of light).
MH produces all of it's heat (and light) in one small location. With fluorescents, this heat is spread out over a much larger area (as is the light), so the lamp surface temp is much lower. This can give the illusion that less heat is being generated, but actually this doesn't necessarily mean the
total heat being produced by the lamp is less.
I know of more than one case where someone switched from a hood packed full of fluorescent lamps, to one with two MH lamps and ended up with a brighter tank and
less heating issues. My tank is easier to keep cool with halide pendents over it than it ever was with fluorescents in a canopy and it's MUCH brighter.
Lots of people use MHs (myself included) that do not use a chiller and have no temp problems. Fans in the canopy, running open top (pendents) and/or a fan over the sump or tank surface will all increase evaporation and therefore evaporative cooling which in many cases is all that's needed to keep temps stable.
JMO
