Do you know anything about your flat regarding the structure and so on?
Did you not do anything in order to make sure you was actually okay putting that size tank in an upstairs flat?
6ft tanks weigh the same amount as say 10 people but the thing is the tank is sitting there all the time where as people are not.
If you go by that definition, what is the actual limit before it is too heavy and the floor could not cope?
I do know that the tank will be going parallel and against a wall and the cabinet is not a four leg support one but the better one that supports the whole tank.
Structural engineers I've read can cost £££ which is not really the issue but this person might just tell me what in already reading as by some sites definitions of what the floor can hold even a 4ft tank is too heavy like I've said yet I know a few people who have this size upstairs in houses a flats.
130kg per square foot is what a floor should hold yet a 6ft tank will be in the region of 700-900kg, there is a big big difference as you can evidently see.