400w flash boil??

[captexas]

I used to run 2 x 400watt halides plus about 220 watts of VHO over my old 75g reef tank. Heat was definately an issue, even with two fans in the canopy. I ended up having to run a chiller.

Even if you downgrade and run 250watt halides, you should still run a fan or two in the canopy. If you have a sump, you can also add a fan in the stand pointing at the water surface in the sump to help cool a little bit.

[so-smrt]

WOW that was more info than i ever thought i would get! i havent settled on a 400w i had a 250w it died. so i neede to replace it and $$ is really tight and i found a 400W ballest for about the same price as the 250w just neede some advice as to if that would be a good idea. thanks for all the help.

[txstateunivreefer]

well on my 100 i run 2x250w mh and 4x 65wpcs so if you got something similar to that you should be in good shape i have all types of coral and they do just fine i have 2x 4" fans in my canopy and im sure i get some more cooling from the trickle evaporation in my wet dry below ( increased surface area of the H20) and my temp stays right at 79 all day and at night fans go off to keep it constant