reef tank causing indoor mold?

[GRocks]

I have noticed a bit of mold growing on one my living room walls since putting my reef tank upstairs, but im not sure if this is due to the recent climate change, a leak in my house/ ceiling, the evaporation from my tank this winter, or any combination of these. I have to tap off my 80 gallon system with about 1-1.5 gallons per day in the recent weather and im sure the water has to go somewhere. I also notice what appears to be condensation on my walls even in dry but cold weather. Either way, ill be trying out a dehumidifier. Does anyone have any suggestions? They would me much appreciated. Thanks!