I'm going to be moving to Philadelphia this summer and my lease says that I'm allowed to have an aquarium in my 5th floor apartment, with no size restriction specified! There was a 90-100g in the landlord's office and I asked if I could have one that size, to which she nonchalantly replied, "oh sure", leading me to believe that a larger one would also be ok. Just how large an aquarium do you think I could get without compromising floor strength in a relatively modern high rise (10 stories or so). I know I would need to talk to a structural engineer if I really wanted exact numbers, but I'm just looking for a rough estimate - what's the largest one you've had/seen in an apartment?