Too heavy fish tank?

[weezer591]

Hey, so about three years ago i was in 7th grade and got really interested in starting a saltwater tank. So for christmas i got a 30 gallon tank. I set it up and waited about 3 weeks to put a first fish in. I guess it was that I was too young and wasn't responsible enough but i didn't clean it enough and fish were dying and all sorts of things.
I want to get a bigger tank and get more into it now, i was thinking a 55 gallon. I want to keep it upstairs in my room is it too heavy for the floor?
Just curious, because I remember back then my mom saying it was too heavy but i think she was just being cheap

(the other day i asked what was too heavy and she said i dont know)

 

[f14peter]

Just saltwater itself is something around 8.8lbs/gallon. Factor in sand, rock an equipment and a good ballpark figure is probably around 10lbs/gallon, maybe more.
A lot is going to depend upon the exact location of the tank in relation to load-bearing structures, its location relative to its long-axis and either parallel or perpendicular to floor joists, as well as age, condition, and construction standards of the building.
There's an article referenced somewhere that discusses home construction and ability to handle a tank's weight, maybe a search might turn it up.
There are ways to mitigate the impact, such as placing the tank-stand on planks, which would distribute the load over a wider area, that sort of thing. Style of stand is to be considered too because many only have a contact surface between it and the floor along the edges, not the entire bottom, and this can lead to greatly increased PSI numbers.
I remember this being a lively topic of discussion in the late 1960s/early 1970s . . . only it was about waterbeds.

 

[garnet13aj]

I read something that sounded reliable that said anything 55 g or under should be okay. I wouldn't take that as an absolute, but I have a 55 in my appartement (I'm on the 3rd floor) and the floor isn't sagging or anything. I'd like to know how to figure out exactly how much weight a floor can hold, but I have a feeling that the process of figuring it out is a difficult one. It's definitetly something to consider though.

 

[weezer591]

yeah^^haha i have a feeling that would be a tough experiment. alright thanks guys!

 

[sfoister]

Hmm I would be interested too.. I'm planning a 75 gal reef and I will be living in an apt. However I don't know which floor... I don't want to wake up in the morning and find my downstairs neighbor swimming with my fishes..... ha! ***)

 

[chuckcac]

Originally Posted by garnet13aj
I read something that sounded reliable that said anything 55 g or under should be okay. I wouldn't take that as an absolute, but I have a 55 in my appartement (I'm on the 3rd floor) and the floor isn't sagging or anything. I'd like to know how to figure out exactly how much weight a floor can hold, but I have a feeling that the process of figuring it out is a difficult one. It's definitetly something to consider though.
f14peter - good advise! but just for fun... figuring that out is done as such;
there are both Dead Loads and Live Loads that are considered in calculating the weight that a typical floor joist system will handle.
Dead Load= weight of all construction material not subject to future movement - (plywood, floor joists etc)
Live Load= weight of things of a variable/moveable nature (people, furniture, Aquariums)
residential sleeping areas (second floors) are designed for a LiveLoad 30psf and a Dead Load 10psf = 40 pounds per square foot -
Now, the part that makes it complicated...
...the entire floor acts as a system to support all the loads together...
so (for example);
a 10' X10' room = 100 square feet... 100 square feet X 40 psf = 4,000 lbs.

the floor is designed to handle that much weight at any given moment
the part that complicates whether or not you can put your tank in your bedroom is;
1. where are you going to place the tank in relatioship to the direction of the floor system...(what direction the floor joists run)
2. is the beam that supports the floor system substantial enough to handle the new load without creating a sag in the ceiling below

55 gallons saltwater (1.025 salinity) = 469.6 lbs
the tank itself= 60lbs +-
LR = 100lbs +-
LS (4 inch bed) = 102lbs+-
filter/lights other equipment = 50lbs +-
for a total of 781.60 lbs -

i dont think this would cause any kind of collapse of your bedroom floor...

 

[xdave]

Hmmmm... very interesting. I've been worried about setting my 65 up. It's acrylic so the bottom of the stand is a solid sheet, 52" x 26" or so. The house is brick with hardwood floors built in 1890. The floors are all tilted so I have to make a platform to get the tank level. There are some bad spots in the floor but is just wear in in the boards traffic areas, they are the original floor boards over 110 years old. The spot where I want it is the most level and it would run perpendicular to the joists. Also the wall that would be behind the tank is in the center of the second floor and in line with the wall of the stairway. It's the top half of a rented duplex and I'd hate to have it do any damage.

 

[chuckcac]

Originally Posted by xDave
Hmmmm... very interesting. I've been worried about setting my 65 up. It's acrylic so the bottom of the stand is a solid sheet, 52" x 26" or so. The house is brick with hardwood floors built in 1890. The floors are all tilted so I have to make a platform to get the tank level. There are some bad spots in the floor but is just wear in in the boards traffic areas, they are the original floor boards over 110 years old. The spot where I want it is the most level and it would run perpendicular to the joists. Also the wall that would be behind the tank is in the center of the second floor and in line with the wall of the stairway. It's the top half of a rented duplex and I'd hate to have it do any damage.
if the house was built that long ago, chances are it was framed with wood that is of a MUCH higher quality than the wood we use today... for a few reasons...
for example; 2"x8" floor joists back then measured 2"x8".
today 2"x8" floor joists actual measurement is 1.5"x7.25".
Also, wood back then was sawn from "Old Growth' trees and was much denser.
these days, trees are mostly farmed to make lumber. So the lumber is not as dense and its Fb (bending stress) is much lower.
doe sthe floor have any "bounce" to it?
your 65 gallon tank would weigh upwards of 850lbs
for both you and weezer, i would imagine it would be ok... But - It's difficult to tell what the situation is going to be without having seen the structure and having the opportunity to do the actual calculations for the floor load...

 

[xdave]

No bounce at all. My neighbor told me that most of the homes in this area were built with the larger trees that were on the lot and they left the little ones. We mostly have huge oak trees on my street. He has one in his front yard that's about 4' to 5' across. All the wood work, including the floors, in our house is oak and maple.

 

[chuckcac]

Typically soft woods such as Douglas Fir or Hem Fir are used in framing structure, and the hardwoods such as oak & maple are used for finishes - such as flooring, trim & moulding.

(i love older homes, they have such charm)
Regardless, i would think you'd be fine with a 65gal in that type of home - most of the housed of that era - (the ones that have been upkept and well maintained anyway) are increadibly structurally sound...

 

[mandarin w]

I am not saying everyone should or could do it. Check it out before you set it up. But most apartments have to be build to higher codes than homes, (at least that is want the engineer my landlord sent over to check out my apt.told me) My land lord sent over the engineer to make sure my floor would support my tank. I live in a third floor apartment. Right now I have a 180 gallon with a 75 gallon sump in my dinning room. A 75 gallon fish only in my living room. A 75 gallon reef and a 50 gallon prop tank in my bedroom, a 29gallon mantis shrimp tankin my son room. All have been up for quite a while now and there is absolutely no issues anywhere. So it can be done. Just don't run out and do it, because mandarin_watcher could and didn't have a problem. Not all building are built the same.

 

[waterworld]

Should it be a consideration in the calculations of the weight of your set-up that if you have a 100 gal tank and add 100# of live rock that the live rock displaces a certain amount of water. This of course means your 100 gal tank may only have in it 75-85 gal of water. That decreases your overall weight. This may be splitting hairs but in the example the decrease of 25 gal = 215 pounds lighter.
I have my 125 gallon on the first floor and built a beam to go under the floor joist supported by two jack posts. Of course not a good option to many.
Good conversation and interesting facts by all.
WW

 

[phixer]

Chuck you brought up several good points...
By adding 100LBS of rock you may only be displacing the volume of a few gallons of water. At 8 LBS a gallon you may be losing 40 LBS but still gain 60 LBS . It's a good idea to consider what your total weight will be when placing a tank on a joisted floor and then inspect your structural supports no matter how thick your beams are i.e (termites / wood rot).
Please read this, it may help to answer some of your questions.
http://badmanstropicalfish.com/articles/article28.html

 

[chuckcac]

Good Points made by all... It's true the rock would displace some of the weight of the water... The rock is very pourous so it would not be an 'even-steven' # for # displacement....
BUT, In my job, i always tend to "err on the side of caution"... its cheap insurance...
mandarin w- yes, multi-family residences are governed by a seperate building code (i'm in NYS) single family residences are R3 construction, and multi-family are R2 or R1 construction... Most of the diffrences between the types of residential construction codes deal with Fire Protection, Handicapp Accesibility...etc.
However, building codes for floor joist/ beam spans are governed by the calculations published by the by the American Wood Council's "Wood Frame Construction Manual" - These standards for wood framing are the same for all 3 types of residential construction, and are used by the IBC to create the building codes.

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