i have two 5 gallon jugs that sit in the laundry room.

I add about 3 gallons every week to the tank.

Over the weekend I started opening all the windows and doors to help aerate the house. I really think the mold problem is in the hvac unit which is in the garage, perhaps in the coils of the unit.

Its strange though because i've had this tank in there for a year with no problems.