landlords are a problem, like someone else said that was one of my motivations for getting a house, i may have a small house but it is full of fish tanks and no jerk to tell me not too!
Katatonic -I don't mean to pick on you, but some of what you wrote is flat out wrong.Wow - dont know where you guys rented... but aquariums are permitted and anything within reason acceptable here... Of course no knocking out walls and such...
IT IS NOT ANY OF YOUR LANDLORDS BIZ WHAT YOU DO IN THE PRIVACY OF YOUR HOME (Wrong- of course it is their business. It literally is their business). The only time he/she may interfere is if your actions are disturbing others and causing risk (You don't think 300+ gallons of water and 3,000lbs+ poses a risk?) ...like with a violent barking dog... or you choose to not clean up after your pets and the smell has overpowered the hallways...(yuk) ... As for fishtanks - They dont care, its for the most part a self contained quiet non obtrusive hobby.. If your all spilly with water and damaging property that might piss em off. (That much water on the 4th floor can cause tens of thousands of dollars worth of damage...think of the costs involved of replacing floors and drywall for OP's unit and all the units below his..."might piss them off" "if you're all spilly" is an understatement).
I do believe the weight ratio is like 8 pounds per gallon (It's 8.33lbs per gallon). Do your tanks weigh more than the fridge and stove stacked together? The answer is, probably not. (Wrong again. A fully stocked fridge might weigh 600lbs, a stove 300lbs = total of 900lbs. The total weight of all of those tanks will be 3 times as much as the fridge and stove).
if you are renting an apartment in someones private home its a little different - their house their rules (Wrong again- renting a house is no different than renting an apartment in the sense that you either abide by the terms of the lease or face eviction), but I assume we are talking about a residential complex...
here's what you need to worry about - How old is the building? and, what are the faucets like? Quality of tap water? Oh and are you metered for hydro individually or is it all inclusive in your rent?
the age of the building will be a good indication of the floor supports (The age of the building has much less to do with the strength than the actual materials that your building is made of) ... no matter what floor you live on. ...
are there stairs or elevators?, narrow hallways?
Are the floors a creaky with rickety wood, can you hear the people bellow you? --- you probably should not have rented there at all...
none the less - if its a condo and you pay condo fees.. or you rent in an apartment complex... the rule of thumb is, you break it you buy it... if you are the cause of some destruction to the buildings integrity - be prepared to pay for the repairs... and if you want to move out - you better put the apartment back to the way it looked when you moved in. (I agree with you here...it's not just damage caused to your unit...if you are the cause of water damage to the units below yours, you are also responsible for the damage).
GET RENTERS INSURANCE! my god it was the most brilliant thing I did - my coverage took care of everything, from fire to flood. Theft, vandalism you name it if anything happened to my home, the contents in it, at my hand, or at my guests hand... it woudl be covered to a huge extent...(Good advice here)
There's a reason several people have mentioned that he should clear having 300+ gallons of aquariums with the landlord...it can be a real issue. One of the things I like best about this site is people sharing ideas that I may not have considered. If he doesn't want to hear it, he can ignore it. But why not ask the landlord about it and find out now if it will be an issue as opposed to having the landlord freak out when they come to service his A/C unit, fix a leaky toilet or any other issue?He's just asking about the weight of the tanks. I really doubt OP wants to hear people telling him to talk to his landlord... Anyhow, I've never had any issues with tanks that size in my second floor apartment. I currently have my 125g 6ft long tank in my living room no problems, and my girl friend has her two 40g breeders on a double stand in the bedroom not on any outdoor wall, no problem. At one point I had a caddy cornered 125g 4.5' long tank in the living room (which was really heavy, pressured on 6 legs instead of all around the stand, and super tall, and also kind of out in the room since it was caddy cornered) with a 95g 5ft long tank right across from it against another wall with no issues. I doubt you'll have any issues with those tanks being nothing you have is really too big. A sofa with 3-4 grown 180-200lb men on it will be getting as heavy as 55g-75g tank and we don't worry about things like that when placing furniture in an upper apartment. I doubt you'll have any issues.