Second Floor Tank

[LBForce57]

Im hoping to put a tank in my second story office and am wondering what the largest tank you have put above the first floor is? What floor support was underneath?

Also, what do saltwater tanks end up weighing after rock, sand and water (not including stand and canopy) per gallon?

I would like to get atleast a 55 gallon, but would will go bigger if at all possible.

 

[BONDQ]

I have a 32 gallon on the 3rd floor of my house.

I think a gallon of water is 8-1/2 pounds.
I used 55 pounds of live rock and 40 pounds of sand.

My tank is about 450 pounds with the tank, stand, and skimmer.
(This includes water, rock, and sand)

There is a structural wall underneath the tank, that extends and perpendiculary crosses down to a structural beam located on the 2nd floor.

Personally, I would not exceed adding 500 pounds to a second or third floor.

The thing about tanks are that they draw people to them and so people want to group up and look inside. This means it's pretty easy to have about 1,000-1,200 pounds located within about 10 square feet. I wouldn't want more than that.

 

[Jasen Hicks]

Approximate 8.3lbs/gallon... i have done some research on the rockwork and most of it displaces about .7 gallons/lb so id just estimate 8.3 lbs/gallon overall maybe 9 to be conservitive. I have a 75 with a 20 next to it, and a 30ish gallon sump on the second floor of my apartment no problems.

Jasen

 

[LBForce57]

Excellent, thanks for the input. I'll do a little research and try to find out how much the floor could support, and then try to figure a safe tank size to have.

Does anyone know any sites that show how much weight certain floor support boards can hold?

 

[toastman]

The foot print of the tank has as much importance as the size of the tank, the larger the footprint the less presure on each floor joist. What kind of building is it? How old? Are the joists 2x8,2x10,2x12, I joists? I hear alot of talk about bearing walls underneath the floor, and well the news is, if the floor is above another level of the building, it has to rest on a bearing wall, period, simple physics, floors dont float. It is better to have the load resting on the first 3rd and last third of a span, not in the middle, as the floor will deflect more the further you go into the span, so around the exterior walls of a building the floor will not deflect as much as it will say 8' inside of that same room. Most residential floors are designed at 40psf, live load, that is the active load on that floor, ie you, your bed your fishtank. And at that designed load that floor should deflect only /360, or basically you take the span of the joist, turn it into inches, and divide by 360, and you will have how much it should deflect in inches. Most of the time its around 1/3 of an inch. The easiest way I know of to figure out how big a tank you can have in your upstairs is to stretch a string underneath that floor (the ceiling of the room below) space it away from the ceiling by 1 1/2" with blocks, and measure the distance from the string to the ceiling in the center of the span. The go upstairs, and add the weight that you anticipate your tank to be by laying whatever means you have, you could just use a group of friends(people have a mean footprint and worse than a fish tank, alot more psf on a human foot than on a properly made fish tank stand), so say you have a 75 gallon tank, cut a piece of 3/4" plywood 48"x18" lay it on the spot you want the tank to go, figure water at 8.5 lbs x 90 gallons(dont forget your sump) ,then add in for the stand, the tank, and the gravel/rock, always better to err on the heavy side, so say it will wiegh in around +-1400 lbs, get that much wieght on the plywood spot, and check the deflection in the ceiling below, make sure your friends like each other, that would be 7(200lb)people hugging each other. Dont let them bounce up and down, thats not a good thing. If your ceiling hasnt deflected more than it should then I would say you are fine....but thats just my simple idea and solution. IF you have a bunch of weights it would be easier to do too, but who has 1400 lbs of weights hanging around.

Dont do this and then sue me, its just one idea, of course check the ceiling as you load thespot, as you get up to your desired weight.

 

[TellyFish]

Over 100 gallons here.

- on the third floor of a rather old greystone 3 flat. So far, so good. I did get insurance however... just in case.

 

[csb]

If your rock displaces .7 gallons/lb, then there's something wrong. (unless I misunderstood your number, then I'm wrong

I have about 30 pounds of rock in 1 tank, and it displaces no more than about 2 gallons. I also just put 15 pounds of rock in a 10g nano tank and it only displaced HALF a gallon!

Your mileage may vary ... and you might want to test some of your rock to see exactly how much water it displaces. THEN, it would be easy to do some math on the weight of the displacement along with the weight of the added rock.

In my case...

30 gallons @ 8.4lb/gal = 252 pounds (water only)
2 gallon displacement = 16.8 pounds
252 pounds - 16.8 pounds + 30 pounds rock = 265.2 pounds

That's 265.2 pounds of water and rock only for my tank. Total weight, after tank, equipment, stand, substrate, fish , probably weighs in at about 500 pounds. (1st floor, concrete slab, I could have a gigantic tank, but I have a 30g and a 10g nano. Go figure)

If you're using good porous rock, it'll displace less water and you'll probably find that for any given added weight of rock, you're probably only adding NET weight of about half the amount of rock due to water displacement. In my example, my NET weight rock addition was actually LESS than half due to water displacement.

It wouldn't really be possible to have dense rock displace more weight in water than the weight of the rock itself... that's called "floating" Although, I'd love to see a comparison example from someone with dense rock!

 

[Jasen Hicks]

I may need to go recheck my number, because after some thought it does seem odd... maybe it was lower... ill do a small experiment with a jug of water and a lb of rock and see how much it changes level...

jasen

 

[csb]

Yeah, it's a good experiment... I'm interested in knowing what you come up with!

--csb