[ichthyogeek]

OP hasn't lost interest...just has absolutely no idea how to proceed. Like I said, the house lies on top of a wooden crawl space, and I have absolutely no idea what most of those things y'all are talking about are. Thus I've just been googling things left right and center. The proposed space is by a partitioning wall (?) that separates the kitchen from the living room (where the tank would be), and said wall is right next to an exterior wall with bricks like so:
(bricks) | OUTSIDE (bricks here)
kitchen |---------------------------------(wall)
kitchen | living room area
kitchen | (proposed tank area)