Placing a Tank on an Uneven Floor

[reefmandan]

So I picked up a 120g (4x4x2) setup from a local reefer here in Edmonton. Tank is really nice, in great shape and sits on top of a square tube steel frame, that is solid like a tank. The load sits on a 4x2 square of tube, as opposed to legs.

The place that I have in mind for the tank is in the living room on the second floor of our townhouse, sitting directly above a floor beam, with the joists running perpendicular (so parallel to the long length of the tank). Left to right, the tank is perfectly level, however it lists considerably coming off the wall. Please see pictures to see what I mean.

I'm wondering what my option are, as I've never had to manually level a tank before. Is shimming part of the stand an option? The stand its on a laminate floor, so I'm a bit concerned about the significant weight resting on shims, possibly denting the floor. Really I'm just looking for some feedback, see what you guys think, experience you've had and what my options might be.

Thanks!