I always prefer to use a hood and covered tank. It minimizes evaporation and keeps critters in the tank.
Hoods keep light from spilling all over the room.
I always make allowances for ventilation in any DIY hood. The one on my 50 gallon salt tank has the back open for ventilation
I mounted a Finnex Stingray LED
bar in a canopy for my little refugium;
for ventilation I mounted fan in the left side of the top (you can see it above) and the same size hole on the right side with a dust filter on it. I also picked up 12 heatsinks with adhesive on them at the electronics store and mounted them on the top of the Finnex fixture so the fins were all in line. When mounted in the canopy, the heatsinks are about 1/2" below the ventilation holes and the air is drawn in on the right, blows over the fixture/heatsinks and is exhausted by the fan on the left.
If I need to remove it, I just unscrew one of the wood blocks holding it in place.
Been working great for about a year and stays nice and cool.
I also mounted the same heatsinks on a 36" Coralife T5 fixture and it makes a big difference.
The 165 watt LED
on the 50 is mounted in the canopy, but the fans and all are outside of it;