Venting is recommended especially if there's a sump.

My stand for my 45g cube is vented with 2x Cougar 120mm fans from NCIX. I bought a 4 pack of Cougar fans for $20 - 1200RPM 60.4CFM 17.7DB.

Since the cube is in the main part of our open floor plan, I'm running the fans at 9vdc vs 12vdc to run them even quieter.

I hope this helps!

I use two fans in opposite corners of the stand. One blowing air in during the day, one blowing out at night:

http://www.jlaquatics.com/phpstore/s...t_ID=cv-sfan04

It also speeds up depending on temperature. I have very little temperature fluctuation using this method during the summer - and don't use a chiller. It maintains my pH and provides good airflow.

Before it was just a sweat camp in the sump area, this definitely improved everything overall. My sump area is also completely enclosed, with a plastic vinyl backing to prevent excess humidity in the room and evaporation. It keeps the evaporation down, and my windows don't sweat (as much.) if it were an open back.