So I just got my 180 together and am debating where I'm going to put it. I live in an older home with no finished basement. Our cellar is divided into 2 sections by a very big thick stone/concrete wall. I currently have a 150 (6x18) footprint on one side of the wall and a 90g (which is no concern to me what so ever). My idea is to replace the 90 w the 150 and the 150 w the 180. There will be about 6" of the 180 that will rely on the floor joists (which are 2x10's on 24" centers) Based soley on water weight (1g=8.35) The total weight of the 150 is 1252.5 or 139.1 lbs per sq ft, and the 180 is 1503 or 125.25lbs per sq ft. Is this an accurate assumption to conlcude that a 180 would be ok in place of the 150? I just got the 180 and it has a very nice stand and canopy and I would really like to have it set up in my living room so I can see it! Thanks for the help.