Excess moisture in fish room

[whatcaneyedo]

My 220gal system is in a 7'x8' room. I'm using a 110cfm bathroom exhaust fan (draws about 1 amp) on a dehumidistat. I also have a 4" hole in the exterior wall to draw fresh (typically cool) outdoor air inside. The humidity in there usually sits around 45% with little to no impact on the rest of the house.

Dehumidifiers produce a lot of heat, require a lot of electricity (our old one drew 3 amps and couldn't keep up) and are typically much noisier than exhaust fans.