Upstairs Tank

There is a very valid reason why a structural engineer is really the only definitive answer you're going to get as to whether the floor will withstand the weight long-term or not and/or the best location for such a tank.

That said, I have had a small, 54-litre tank on a sideboard in my living-room for 2.5 years. It's by an external wall. The flooring and the skirting board in the corner behind/underneath the tank now have a 1 cm gap between them.

In the other corner, there is a small, lightweight bookshelf, with enough space to see that this hasn't caused a gap between flooring and skirting board. Previously, a larger fishtank and stand occupied that location for 11.5 years - I can't recall whether a gap between flooring and skirting board existed but which has now retracted since the heavier weight is no longer there.

A neighbour has a 200-litre tank on the opposite side of his living-room - I don't know whether or not this has affected his flooring, but, from general discussions with the neighbours in the same block of flats, there is quite a bit of variation between flats in terms of any problems encountered even when on the same side of the building, so an entirely different answer could apply if each were to have a fishtank in the same (let alone a different) location in their flat.

Hope that's helpful.

I'm actually in a house rather than flat if that somehow makes a difference. I'm getting the fluval roma 240 and the tand associated with it which has 2 contact points. The wall it'll be against is load bearing and I believe the joists run right through the house in such a way that the tank would be on several, but I need to double check this today.

More curious about how the hell you got that upstairs now That's fairly reassuring though.