I have my 180 on my second floor, but I checked with an engineer before I put it there. My house is built like a tank! The drama of falling through the floor is a fun thought, but very rare. More likely is sag caused over time. Check with experts about how your floor is rated....it will pay for itself in equity when you go to sell your house! Also make sure the tank runs parallel to the weight bearing walls; this helps to distribute the weight.