Fish tank in condo

[patman]

Not sure on your weight calculations. 1 gallon of water is like 10 lbs. Your 60" tank sounds like about 130 gallons so about 1300 lbs just for the display tank water. I know there isn't that much water as rocks and substrate displace it, but they also add to the weight. Then add in the tank weight, sump, equipment, ..... My place was rated for only 75lbs/ft so I ended up re-enforcing the floor between the joists to spread out the weight. Best if you can do it near a load bearing wall.