Malt_Vinegar
Fishaholic
Try and find a story on the internet anywhere of a tank going through the ceiling. I dare ya
120L should be fine, I weigh more than that and my floor is dodgy (Old victorian built)
If the building is purpose built the floor will almost certainly be reinforced concrete and capable of supporting far more than normal floorboards. Probably the only limitation would be getting the tank to the flat.