my 180 plus my 55g sump are on the second floor of my house. no problem with yours. If you are still worried, exterior walls and the walls around your stairs are gauranteed bearing walls. Most walls in your house are not bearing. 2x10 floors are stronger than TJI's. If your tank is 36x18 you are pretty much gauranteed to hit at least 2 joists. Most joists are on 16" centers. Aquattro is right about everything, plywood spreads the weight more than you would believe. I weigh 240#(don't tell anyone) I would noy hesitate to pick up my 120# girlfriend, my 40# kid and my 90# dog. I would stand on 1 foot for about 1500#'s per square foot. no problem

Absolutely no worries at all! How buot a jacuzzi tub on the top floor?

Provided your house is structurally sound (not rotted, or 150 years old), your tank is too small to be an issue even if it only hits one joist.

The house is 18 years old and plywood is solid ( I just re did the flooring last year with 8.3 mm laminant -wish I went 12.3) I'm glad to hear it shouldn't be an issue.

I dont know about anyone else but, new but handy I'd like to see you test that theory and pick up your GF, kid and your dog all with you standing on 1 leg :)

I think my stand will start then this weekend.

Cheers everyone !!

The tank wont be an issue. If you are still concerned you could put a tele-post in under the tank(assuming the basement is unfinished).