Floor will be fine. A fully stocked refrigerator is probably comparable in weight just for a comparison.
Its only a concern really once you start getting into the hundreds of gallons. But as stated check with your landlord or check your lease for any regulations on aquariums or tank size.
Ive heard of some apartments having a 20g max in the lease just FYI. If the tank would flood and cause damage to the floor your on or the ones below it, your liable for everything. But personally ive never experiences a lease or a landlord that had anything against aquariums and ive been renting for years at several places.
I would imagine complexes with multiple floors will have more of a restriction than say a rented house or a duplex etc where your not gonna start destroying other peoples stuff if your tank cracked, flooded etc.
29g Mixed Reef, 150w 14k Phoenix MH w/ Moonlights, Reef Octopus BH1000 HOB Skimmer, Ecotech Vortech MP10es, ReefKeeper Lite (Plus), PH Probe, Temp Probe, ATO, Carbon/GFO Reactor.