# How large of a tank can a floor support



## benealing

I know there are probably entire books/university courses on this type of information. However, I am interested in how seasoned aquarist determine what level of their house to place a tank on.

My house is two stories with a basement. The basement is slab concrete. The first floor is hardwood. The second floor is my twin 3 year old's demilitarized zone and not habitable for fish

This winter, I want a much larger tank than my little 20 gallon. I would prefer it go on the main level of the house. I have a half wall between my kitchen and living room and would like to have the tank in that area.

So, are there any common sense guidelines I can use other than hiring a structural engineer? I am not looking for a mega 600 gallon tank. Maybe 75 gallons.

Thanks,
Ben


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## Coralbandit

Most every building should hold a 75 without issue.
Go in basement and see which way floor joist run.
You would prefer to install tanks perpendicular to the floor joist,but this is not completely necessary.


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## benealing

That is the type of answer I was looking for.

Incidentally, what size tank do you begin to worry about the floor supporting the tank? I know people have had waterbeds on the second floor of the house, but that is also a very large footprint.

Ben


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## Coralbandit

I have my 180 on an outside wall running parallel with floor joist.
I added support(post) to the header(beam) that holds up joist since that is exactly middle of my 6' tank.
In the 80's I had a waterbed in one room,135g in next and a 100g in the next in a second floor apartment(oh to young and foolish again!)


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## benealing

Since my basement is unfinished and I can see everything, I guess I will make a trek down there to see how things look. I can't imagine my wife supporting the purchase of anything bigger than 75 gallons, but if I can get all my ducks lined up....who knows.


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## chris_ranger

You will be fine for 75, be aware all houses are different. Building codes, sub floor material, joist spacing, joist type, and direction of joist plays a huge factor into how much a floor can hold.
A 75 is 48" wide, when running perp to joists will span at minimum 3 joists. Tank will weigh close to or over 700 lbs.
http://www.cichlid-forum.com/articles/aquarium_weight.php


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## dragam21

Most floors in newer homes or older ones should hold a 75 gallon tank without any issues!


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## lksdrinker

Yeah I wouldn't worry too much with a 75 gallon tank. Would you be concerned if 4 grown men stood close to one another having a conversation in the middle of your living room? Their total weight probably exceeds that of the 75 gallon tank. 

You should still check the joists and try to place the tank in as safe an area as possible though. Exterior walls are always a better choice than interior walls; but not necessarily the only choice. Same idea with tank placement. Best choice is perpendicular to the floor joists but again not the only choice. 

As far as the wife goes however....buy the biggest tank you can afford and safely fit in the house now and ask for forgiveness later! Or get clever and pickup something like a 150 gallon extra high tank....same footprint as a 75 gallon ( i think?); but twice the water.


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## benealing

Thanks for the link. Very helpful.

Also, I really like the advice on the wife issue


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## Blacktetra

One thing not mentioned, worth keeping in mind is how the tank is supported. obviously if you put the tank on a metal stand with legs that are shaped like daggers you'll end up with metal daggers hanging from your basement ceiling. I know it's pretty common sense, but joists can help only so far as the weight is properly distributed across the plywood placed atop them.


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## navarro1950

My 125g tank is setup on an outer wall across 4 or 5 joist and holding great. I used 14 bags of eco complete at 25lbs per bag and a 1" cap of very small gravel at 50lbs per bag. Water weights 8.5 lbs per gallon. You also have to think about water displacement than estimate the weight of the tank plus the weight of the stand.


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## MarkM

I have a 120 and a 50 in the same room about eight feet apart. One is perpendicular to the joice and the other parallel. The 50 will be replaced with a 300 soon. I added some additional support under my floor in the crawl space under my home. I installed four foundation pillars and two six inch I beams on jacks. This works out on paper to be overkill but it is a new house with wood floors and I did not want to take any chances.


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## benealing

Is adding support to the floor something that a complete novice should even consider doing? I am in no way handy. It is again also just for the sake of asking as I still can't see getting more than 75 gallons. But like I said, get my ducks in a row and see what happens.

Ben


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## The Dude

benealing said:


> Is adding support to the floor something that a complete novice should even consider doing? I am in no way handy. It is again also just for the sake of asking as I still can't see getting more than 75 gallons. But like I said, get my ducks in a row and see what happens.
> 
> Ben


I'm not positive, but I believe you can get a 125 that is two feet longer than a 75. The rest of the dimensions are the same. That's what I would do. After my wife spent a while with my tanks she grew to appreciate them as living art. I have 5 in our condo. Now down to one 75 gallon. Shes asked me several times when I'm going to setup the shrimp tank as she would.like it in the bedroom and also told me she is excited for the 180 gallon that I'm going to do in the main sitting room. Take care of them and your wife will learn to appreciate their beauty. I have my 75 set up in the exercise room near my treadmill and there is a large half circle chair In front of the tank. It's the most popular place.to sit in the house. There is almost always someone in there sitting staring into the tank


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## me_in_the_box

If you don't know what you are doing your added support will probably not actually help at all. post a picture of the ceiling in your basement under where you want your tank to go. I'm not a structural engineer but I've done my share of home remodels.


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## benealing

I just went down and looked. And as it turns out, where I would love the tank to go, it would have to be oriented parallel to the joists. Here are some pictures.

Unless I put it somewhere else, is it completely out of the question to consider a 120 gallon or larger tank parallel to the joists?


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## Coralbandit

No engineer ,but I build what they and the archs tell me to?
You could place a 120 on that floor,in the middle even I believe.
It would be best if you knew where the joist were when placing tank(18" OR 24" WIDE) so that it "landed" on 2 of the joist.
You could have a placement that would land tank(and all its weight) on 1 joist.(not ideal).
That being said ;1200 lbs. over 8sq' is only 150 lbs per sq'.
Everybody has stood on one foot before(more then 150 per sq' in most cases.)
Best to land it on 2 joist.
Are they 2x12 or 2x10 ?
They look like 2x12 to me with a 16' span from paralam to foundation in pics.


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## blt

As someone who draws and builds houses, I wouldn't put a tank there without reinforcing or consulting an engineer first. Putting a significant load, mid-span, parallel to the joists isn't something factored into standard floor framing. That being said, you may very well be fine as is, unfortunately only a structural engineer($$) would be able to give you a clear answer, and be weary of suggestions from anyone else. Here is a good read on the topic: http://badmanstropicalfish.com/articles/article28.html


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## TRENT

You'll be fine....


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## GraphicGr8s

One thing I don't see is any type of blocking or X-bracing. While it may be just fine I'd find a way to get some in there. Our house up north had a shorter span with rough sawn 2x 12 and had X bracing. And the lumber itself was a lot stronger back when that house was built not the quick growth stuff used in the last 20 years or so.​


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## burr740

Buy a 120 and tell the wife it's a 60. She'll never know the difference.


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## jjp2

You should be ok, but If you have any concern, place a 4x4 perpendicular to the joists in the middle of the tank and support it with a4x4 or post jack to distribute the load. No matter what size you get, you'll be around the 150 lbs per sq ft. Your actually better off with a bigger tank to hit more joists both ways.


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## chris_ranger

Use this to support the joists.
http://www.homedepot.com/p/Tiger-Brand-Super-S-Series-8-ft-4-in-Jack-Post-J-S-100/100022783


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## FishStix

I have a 180, and 75 gallon sump running parallel to the joists, but I did have the person that built our home as was only about a year old at a the time, come in and put in cross braces in the area as well as several support jacks and bricks down to the ground. My guess is it overkill, but I plan to be in this house a long time and did not want to take any chances. If it were my house yes I would have something done.


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## Clear Water

Most house are design for 100 pounds per sq. ft. But a lot of them will support 200 pounds per sq. ft. A 72 x 24 x 24 that would 180 gallon tank witch lets say maximum load of 3000 lbs divided by 24 square feet would put it at 250 pounds per sq. sf. A 75 gallon would be closer to 125 pounds per sq. ft. You should be ok with a 75 as long as it close to support wall.


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## Tank.In.It




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## Kubla

That looks like a well built floor. It's not standard but from the pics it looks to me like the floor joist are on 12" centers. They're closer than the wall studs that look like standard 16" centers. Other than the wiring it looks like it would be pretty easy to just add another joist or 2. You could also strengthen the joist or joists that your sitting above by attaching a 2x4 or 2x6 to the top of the joist. It would have be attached well to be effective. Construction glue and screws should work well. If you're really concerned you can sandwich the existing joist between two 2x4's at the top and 2 at the bottom, ike a wooden I beam. That would be quite strong as long as the 2x4's are well attached and looks like it could be accomplished without the wiring being in the way.



Tank.In.It said:


> View attachment 1026048


I think you need to include the span in this.


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## Liquidgarden

benealing said:


> I know there are probably entire books/university courses on this type of information. However, I am interested in how seasoned aquarist determine what level of their house to place a tank on.
> 
> My house is two stories with a basement. The basement is slab concrete. The first floor is hardwood. The second floor is my twin 3 year old's demilitarized zone and not habitable for fish
> 
> This winter, I want a much larger tank than my little 20 gallon. I would prefer it go on the main level of the house. I have a half wall between my kitchen and living room and would like to have the tank in that area.
> 
> So, are there any common sense guidelines I can use other than hiring a structural engineer? I am not looking for a mega 600 gallon tank. Maybe 75 gallons.
> 
> Thanks,
> Ben


Make sure to put a level on top of your tank after filling it to check for floor sag.


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