I haven't seen it for months, it was a huge concrete reef setup, had photos of the owner diving in his tank to clean the glass... can't find it for the life of me.
Yah Mr.4000 posted over at reefcentral's large tank forum a while back. It wasn't in his basement but in an actual room I though. Anyways yah he had massive humidity problems and made a mention of his walls literally dripping with water every morning which lead to mold/mildew issues.