Fish tank weight & floor support (2nd floor)?

Question

I am worry that my fish tanks are destroying the building structure. I live on the 2nd floor of a two-floor condo, and I have one 60 gal. & one 37 gal. fish tanks sitting on an “L” shape corner of the living room. Every time I walk by the tanks, I see the surface water in the tank waving.

Please tell me it won't happen – I don't want to see my fish tanks travel through the floor and land in my neighbor's living room downstairs one day.

Answer 1

Whether your tanks are safe or not depends on the area over which they are imposing a load. Domestic floors are often constructed to take about 150 kilos per square meter, or about 400 pounds per square yard. The water in your tanks weighs about 370 kilos, a bit over 800 pounds, so if their area is over two square yards you should be OK. If they're standing on tables, though, you might want to put some boards under the table legs to spread the load a bit.

Answer 2

Be careful when opening and closing the door (Only cause fish are so sensitive). My dad lives in an apartment building that's 2 stories. The people on top can't have a tank bigger than 30 gallons. Every two months the owners do walk-in visits too to make sure no one sets one up. You should ask the owners of the building what it can hold. What a mess all that water could make during an earth quake. They may take that into consideration.

Answer 3

The total weight of these AQ's is 809.5 lbs.

There are two things here:

1) This is the *combined* weight. This isn't significant unless they occupy the same (stacked on top of one another), or nearly the same space on the floor.

2) The quantity to be concerned with is not just the weight, but pressure.

Pressure is force per unit area. You could have AQ's weighing 2 tons, and if they were spread out over a wide enough area it would be of no concern at all.

I'm assuming these are rectangular AQ's. Roughly speaking you'd have a tank that is about 48" x 13" x 20" (55 gal). Same for the 37 gallon tank, except the height is different, but the footprint is all that's necessary anyway.

Water weighs about 8.345 lbs per gallon. This gives you:

500.7 lbs for the 60 gal tank and 308.77 lbs for the 37 gal tank.

So, for an area of (48" x 13") = 624 in^2 = 4.3 ft^2 (60 gal tank)

Note: Like I said, this is the same for both tanks, only the weight is different for my back-of-the envelope calculation here.

Then:

For the 60 gal tank, you have a pressure of:

500.7 lbs/4.3 ft^2 = 116.4 lbs/ft^2
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For the 37 gal tank, you have a pressure of:

308.77 lbs/4.3 ft^2 = 71.81 lbs/ft^2

Based on some old, but probably valid flooring data I found, a reasonable guess of the strength of a typical, healthy wood floor is about 200 lbs/ft^2.

Based on this I'd say you are just fine. Just malke sure the floor doesn't get wet and rot, and of course, no one knows what's going on at the joist level of the floor; dry-rot, termites, age, etc. But I'd say you are in a comfortable zone. If you feel unsafe, place whatever the tanks rest upon on top of a piece of FLAT marine plywood (or wood of choice...as long as it's flat) that is about twice their area: (96" x 26"), this will cut the pressure exerted by the tank on the floor by half.

The idea is to spread the total force of the tanks (and stand, etc) over a wider area to cause less pressure per unit area.

Hope this help you.

p.s I believe mr. lewis brown, ahead of me, has more current data, and 'his' numbers support this calculation, with even more room to spare.

Answer 4

60 * 8.33 (lbs per gallon) = 499.80lbs
37 * 8.33 (lbs per gallon) = 308.21lbs

Adding the weight of the tanks, there is probably over 1,000lbs of weight in that corner. It is impossible to know if the floor structure can withstand that weight over time without knowing where the support is underneath.

Beyond that, there is probably something within your Homeowner's Association Handbook that addresses this issue. Have you tried calling them to get the specifics on your building and information regarding liability should something happen?

Good luck

P.S. I have a 55 gallon and the water "bounces" around also. I think it comes from any movement in the area and not necessarily a substandard floor support. I've only seen it not happen when the tank is sitting on concrete.

Answer 5

As long as the floor is not rotten it probably is not a problem. Vibration is normal. I live in an old house and the 5 lb chihuahuas trotting across the floor shake me sitting in my chair. If your tanks have a large weight bearing surface area on the floor they will be fine, especially in the corner. You can increase the weight bearing areas by putting a thick board or tile under the aquarium feet.

Answer 6

that is a lot of weight in one corner. it wont fall throught but it will warp the boards on in the floor, and your downstairs neighbor may complain about his sagging ceiling.

Answer 7

THAT'S ONLY ABOUT 1000 POUNDS IT SHOULDN'T HURT THE BUILDING UNLESS THE BUILDING IS A PIECE OF CRAP.