Question about tank weight on 2nd floor.

[K9]

OK, this one's for the carpenters, architects and engineers in here.

My wife and I have a 2-story stick built traditional home (built in 2001) with vinyl coated aluminum siding and a 5' high brick crawlspace foundation. I'm considering putting a 120g tank (48x24x24) on the 2nd floor in our bonus room, which is also my "man cave". The thing I'm worried about is that the bonus room is over our 2-car garage and there is no way to reinforce the floor from underneath if I wanted too. Also, the wall I have picked out for the tank has a bathtub on the other side (not sure if that has any impact or not). Now I know for a fact that five 200-pound people could stand in the corner and the floor wouldn't give, but I'm thinking about the long-term structural impact of a half-ton of water sitting in the corner. I don't know the dimensions of the floor joists, but I'm pretty certain the subfloor under the carpeting is 3/4" ply. If the desired location isn't acceptable, I could put the tank along the middle of the 18' long wall instead. Diagram below.

Any help or suggestions would be greatly appreciated. I'd like some assistance on this quickly as the tank is for sale locally and I'd like to jump on it soon. Thanks.

[Jeff000]

Just remember, people put water beds in the middle of floors for a LONG time without problems. A queen size water bed is ~190 gallons, and a king is over 230 gallons.
I would personally try and get it to run parallel to an outside wall rather then perpendicular but really shouldn't matter.
The wall you have it running parallel with should be load bearing, that or the one the door opens onto, but I say that only because in general around here the plumbing chase is a load bearing wall almost by accident..

[BrianOKC]

I agree with Jeff. Code regulations for most city/states will support that amount with ease. However I would try and position it to run parallel to an outside wall as well. I mean we should be looking about 1500 pounds at most spread across 8 square feet.

[mattsummers]

you need to know which direction the floor joist run, the tank needs to be across the joist

[K9]

Thanks guys for the advice. The waterbed thing didn't even cross my mind! I found out from looking at the ceiling in the garage that the joists run parallel to the 16' wall, so putting the tank along the 18' wall would have it cross over 3 joists if I placed it right. Plus, the exterior wall is obviously load-bearing, so I think that solves it. Thanks again.