How to know if it can support weight?

[captmicha]

I want to set up a 29 gallon in my room but I don't have a stand for it, but I do have a nightstand that I'd like to put it on. Or maybe the dresser, or some other such surface. The problem is, how do I know if any of these surfaces can support the weight? Is there a formula that will tell me or something?

[cellodaisy]

1 US Gallon of water = approx. 8.35 lb

so 29 gallons = approx. 243 lb

Plus the tank itself, substrate, decorations, etc.

What I usually do if I'm not sure is just stand on the thing and jump a bit and see if it feels sturdy, but that's hardy scientific.

[captmicha]

Problem is I'm under 100 lbs myself.

[cellodaisy]

Problem is I'm under 100 lbs myself.

Rub it in, why don't ya. :silly:

;)

Here's why you can still test this. I'll try not to get too technical.

Pounds are actually a measure of force as well as mass. A person who "weighs" 100 pounds is exerting 100 pounds of force against the earth. On a different planet, under different gravity, they would exert a different amount of force.

You can also exert more force against the ground by falling from a height. It's difficult to calculate the force exactly, because you would probably bend your knees to soften the impact, but we can approximate.

Here's a handy calculator: http://hyperphysics.phy-astr.gsu.edu/hbase/flobi.html

Let's say you weighed 90 pounds (about 41kg). Let's also say that you can jump 1 foot (about .3 meters) and by bending your knees you travel 6 inches after impact (about .15 meters). According to the calculator, you would be exerting 803 Newtons of force on impact, which is about 180 pounds.

So by jumping only 1 foot, you can essentially double your own weight. By jumping 1.5 feet (assuming the same knee-bend), a 90 lb person could exert 277 pounds of force.

Someone please correct me if I've screwed up the math, but the basic point is that you can exert a surprising amount of force by jumping, even if you are tiny.

[SubRosa]

Jumping up and down on a piece of furniture won't tell you if it will support a tank long term. Water is relentless and it wants to be on your floor! You need to look at the individual piece of furniture from a structural standpoint. Where are the load bearing members? How sturdy are they? A piece of furniture which can support 1000 lbs with ease could fail to hold a tank weighing 1/4 of that if the tanks weight isn't properly located on the structure. A nightstand will generally have its load bearing members along the sides. If the tank completely and exactly spans the top from one side to another that is the ideal. A bit of overhang on each side is ok, but no more than an inch or two imo. If the tank does not span the top completely from side to side the piece is not suitable for the tank. Hope this helps.

[dundadundun]

i think the theory is right.

i just see this going soooo bad when she finds out the stand isn't suitable. excuse my sick sense of humor but i'm rofl here.

captmicha... surely you have a bulky friend who can test it for you. (maybe a built guy... not necessarily somebody "big") it would be much safer taking it little by little.

also... she won't be able to test it because at her weight she will not be accounting for real life situations. say it stands up to the jump and pray method and after she gets the tank up she loses her balance and knocks it on the side. the 2 separate forces will now hove a profoundly different effect on things considering the sideways force will jumpstart he downward force as the joints tear apart. (hypothetical of course)

if you have things of known weight you can stack on top of it you might be able to pile it up to something similar and try to knock it around a bit... might be a little more realistic of a test.

[toddnbecka]

A dresser that's made of solid wood (not sawdust and glue) will certainly be sturdy enough to support a 29 gallon tank. I'd recommend placing something waterproof between the furniture and the tank though, sooner or later it's going to get wet.
The nightstand may be sturdy enough, a pic would be helpful.

[cellodaisy]

Jumping up and down on a piece of furniture won't tell you if it will support a tank long term.

You're absolutely right. Like I said, the "jump up and down on it" method is hardly scientific. I was just trying to assure the OP that weighing less than the tank is not the issue.

[dundadundun]

what subrosa posted too, lol.

[cellodaisy]

i just see this going soooo bad when she finds out the stand isn't suitable. excuse my sick sense of humor but i'm rofl here.

:lol2:

Yeah, when I do this, I get on gently and start with very small jumps. If the thing seems rickity, it stops there!




if you have things of known weight you can stack on top of it you might be able to pile it up to something similar and try to knock it around a bit... might be a little more realistic of a test.

Agreed.

[RodInCALIFORNIA]

i have a couple 300 lbs aunts you can borrow for testing :)

[BioHazard]

Yeah, I tested my stands using the put-my-fat-butt-on-it test too, lol. Luckily (?) I weigh enough that I was able to easily test a stands ability to hold a 10 gallon tank, and at least feel more comfortable about the stand for a 25 gallon tank. :)

[cellodaisy]

Luckily (?) I weigh enough

Glad I'm not the only one! :p:

[Rbishop]

A pic of the stand might help us make a call...personally, with so much of today's bedroom furniture being types of particle board and all but cardboard panels on the back, I wouldn't trust them. Easier to spend $10 for some cinder blocks and a piece of plywood..paint or drape a cloth around it.

[captmicha]

Hmm, it's an antique table. Has a radio built into it. Weird, I know. I'll swipe all the junk off the table and take a pic today. I wouldn't want anyone to see it in it's current position and know what a slob I am :headshake2:

If it's not suitable, I'll just wait until I get the huge dresser and table replaced with smaller ones and then I'd be able to fit in an actual tank stand or two.

[jeninok]

I don't jump, that is just asking to break something because I am a clutz, but I do stand on them and do a little dance and lean from side to side, I want to know that it is stable both up and down, but won't easily lean either.

In the case of a big tank I have other people stand on it/move around with me.

You could also add bracing in the form of metal brackets, or some pieces of wood to the underside of the tank where it would be hidden.

[J double R]

I'm pretty paranoid about things like that, and if I even suspect that something might not be sturdy enough, it's not worth testing, I just won't use it. Better safe than sorry.