I am planning to move from a 55 gallon aquarium (625 lbs filled weight) to a 125 gallon aquarium a(1400 lbs filled weight). Do I need to reinforce my floor in my house?
Ok, then that should be ok. what is the heaviest thing that you have in the house that's the easiest to move? I would just put that there. Then leave it for a day or so or get everyone in your house to sit or stand on that zone. That's the only way to find out I think.
If it's downstairs, you'll be fine almost certainly. You may want to call a friend or trusted local builder for advice if your house is older, or you feel some bowing of the boards.