Humidity problems for large tank

[fkshiu]

I had an ultra-quiet Panasonic bathroom fan installed above my 150g system in my basement. Simple and works great on a programmable timer.

I don't know about the "drawing air out and not replacing it" theory - if that were true houses would be imploding on a regular basis from the vacuum created everytime someone took a huge dump after some Mexican food. The fact is that the air drawn out by a bathroom fan is being replaced by air from elsewhere in the house. No house is 100% airtight. If you want to be sure just pop open a window for a bit to make sure fresh air is coming in.