# tank stand question



## coonie (May 23, 2011)

i have a 45 inch long dresser and a 48 inch long 55g tank....if i put this tank on there with that over hang am i gonna have any problems? moving soon need advice...thanks


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## 13razorbackfan (Sep 28, 2011)

Yes...your tank needs to be supported all the way around. It needs to be at least flush.


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## pistolpete (Dec 28, 2009)

I respectfully disagree  having a 1.5 inch overhang on each end will be no problem at all. What I would be concerned about is the dresser holding the weight. dressers are not designed to support that much weight. With something like a 20 gallon tanks it's no problem, but at 55 I'd be checking with a carpenter. Maybe post some pics.


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## 13razorbackfan (Sep 28, 2011)

No...the tank should be supported all around the trim. It should not hang over 1.5".

Taken from another forum as someone else posted a similar question...response from All-glass Aquarium Co.:

_*The most important factor about a tank set up is that all four corners
need to be supported equally* and the tank needs to be level, if there
is
a gap it is probably due to the frame being warped a little, and in
time
it should straighten itself out with the weight of the water in it.
You do not have to be concerned too much about this.
Sincerely,
Charlene
Customer Service
All-Glass Aquarium Co., Inc
[email protected]_

They(most standard tanks) are made to be supported all around the edges especially on tanks holding more water. 55g is a lot of weight and I would be afraid the seals would break as they are not being supported all the way around.

I thought at one time I didn't need to follow manufacturers guidelines in building a stand for a 240g tank and as soon as I filled it up...the entire bottom glass broke and I had to order another large piece of glass to silicone on top.

I would not risk it. 55g stands are everywhere for real cheap.


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## Number6 (Mar 13, 2003)

*pistolpete*
It is essential that the four corners of a glass tank are supported. The overhang may never be enough to cause leaks, or it could cause a sudden blow out of a tempered glass panel. I am not smart enough to understand all of the mechanics of the "why" but a structural engineer once explained it to me because of how the weight of the water is transferred to the structure.

If this is an acrylic tank, 100% of the tank needs support.


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## Rhinox (Sep 10, 2009)

:shrug: I'm an engineer and nothing is jumping out at me as to why leaving a 1.5" overhang on each end would be a problem, if it is a glass tank with plastic trim. I too would be more concerned about the dresser not being designed to support the weight - not necessarily vertically, but not having the proper structural support to prevent "racking".

Just for some rought numbers, I'd say the weight of a full 55g with rocks and substrate might be around 600lbs. The trim of the tank has about 60 sqin of contact area, so if its all supported equally, it has an average contact pressure of 10 pounds per square inch. If you overhang the ends by an inch and a half each, the area in contact drops to about 45 sqin, for a contact pressure of about 13psi. An extra 3psi does not seem like a significant increase in pressure on the tank trim to cause any problems.

thinking in terms of uneven distribution of loading, first realize that the bottom pane of glass is attached to all 4 sides and held in place by the shear strength of silicone. The force is distributed evenly to the 4 panes of glass and carried vertically through the trim. There is also outward pressure on all 4 sides. The sides are held in place by the normal strength of the silicone attaching them to the bottom pane, and also by the normal and shear strengths of the silicone up the sides. The lack of support under the last 1.5" on either end does not change any of the loading on any of the seams. In terms of moments, the moment arm is too small (1.5"), and the load hanging out over the unsupported end is too small (1.5/48 * 600 = 18.75lbs) to worry about any sort of bending load.

That is all the loading I can see that would show up in free-body diagrams. I don't see any additional load I would have to place anywhere as a result of there being no support directly under the ends. Maaaaaaybe the only thing would be the weight of the end panes of glass themselves would exert an additional vertical shear stress on the silicone (which is there even when the tank is empty and not supported on the ends, by the way), but I suspect the silicone is strong enough to support the glass, not to mention the trim will also be supporting the vertical weight of the glass, so... Thats all I got. I can't come up with any reason that leaving an inch and a half unsupported on the ends would cause any problems, and if it were my only option, I would have no problem setting up a 55g tank that had such an overhang.

As correlating evidence, I offer that the ends of my 10g fry tank overhanged on the rigity end table it was set up on for a couple years, and it never had a problem 8)


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## Steve C (Oct 9, 2011)

I'm no expert...but IMO when you have a tank that is designed to be supported on 4 sides (front/back/left side/right side) then if you put it on a surface where the left & right sides are hanging off then you are only truly supporting it by 2 sides (front & back).

I really don't think it is a matter of square inches being supported ...but more a matter of "equal support" on all four sides.

I see conversation on here all the time where people are very staunch about telling people they need to make sure a stand is built with the 2x4's running a certain way, or to make sure the pressure is not on the hardware and that the tank is supported by vertical wood equally at each corner etc etc...so it seems weird that people would be so staunch about making a stand exactly a certain way, but then say "yeah sure let it hang off the ends" :lol: (no offense to anyone there just pointing something out is all) :wink:

Personally I would not do it. That's just my opinion though for what it's worth.


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## PfunMo (Jul 30, 2009)

I live in a college town where improvised support is standard. It is often done and while I don't do it, I have never seen or heard of it causing a problem. If the dresser falls down, you have a problem.


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## lucid_eye (Apr 12, 2009)

I may be over simplifying this but imagine a 4x8 sheet of glass sitting on top of 4x8 table. Would you sit on it? Sure why not. Now put that same sheet on on a 4x6 table would you sit on the edge of that glass? The glass and frame has a certain amount of flex and all of that flex will concentrate at the edge of the supporting surface. You need an equal or greater force pushing up on the table than that of the tank pushing down everywhere. This my work for a while but eventually I am sure you will end up with wet carpet. I am not an engineer so I apologize if I my terminology is inaccurate. One more analogy hold a tree branch by the ends and swing it down over your knee, try holding a tree branch by both ends and swinging down at a table. You are essentially creating a fulcrum anywhere you let the tank hang off.


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## Rhinox (Sep 10, 2009)

*lucid_eye*
With a sheet of glass laying flat with a 1 foot overhang on each end as you describe, and the weight of a person sitting on it, you are absolutely correct.

But an aquarium is a box structure with a high bending moment of inertia. furthermore, we're discussing a 1.5" overhang on each side, not 1 foot. Finally, the unsupported weight is approximately 3-4% of the full aquarium weight on each end, which is only about 20lbs, not the weight of the person.

So, 20lbs acting at a moment arm of <1.5" on a box beam stucture with a very high bending moment of inertia is entirely different than a person sitting on the end of a thin piece of glass laying flat over a 1 foot overhang. Thats like saying I shouldn't sit in the plastic chair I'm sitting in because an elephant standing on a plastic box would crush the box. Its THAT different of a scenario.

you have the right principles, you just have to apply them to the right scenario.


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## des (Mar 30, 2011)

Please do not use the dresser. Find a proper stand that will support all four corners. Why take the risk?

A test for everyone.
Take a piece of paper and try to slide it between the bottom of the tank and stand right at the middle. Then try it again on one of four corners. Where is the weight most distributed?


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## newforestrob (Feb 1, 2010)

I have a 4 ft. 75 gal. on a metal stand that bows(the metal) across the length,in the middle of that span is an 1/8th inch gap,I was told that it is important for the tank to be supported on the ends,I really doubt the tempered bottom pane is going to sag


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## cantrell00 (Oct 30, 2010)

The support isn't really needed at the sides at all.

It is the four corners where the tank makes contact that needs the support. This is on a typical glass aquarium..

Acrylic is a different story altogether.. The entire bottom of an acrylic tank needs to be supported.

In the image below, the 30 gallon that is on the top right doesn't have a support over the entire length of the back glass EXCEPT at the corners. It has been sitting there in that same position since July.


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## Number6 (Mar 13, 2003)

*Rhinox*
I used to say it was no problem until this structural engineer came along and "corrected " me. 
There could be details that differ from that scenario to this one so perhaps this tank will be fine. 
Thanks for weighing in! :thumb:


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## newforestrob (Feb 1, 2010)

cantrell00 said:


> The support isn't really needed at the sides at all.
> 
> It is the four corners where the tank makes contact that needs the support. This is on a typical glass aquarium..
> 
> ...


that stand worries me,I would extend the verticles to the floor,right now you are relying on shear strength of the hardware


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## cantrell00 (Oct 30, 2010)

newforestrob said:


> cantrell00 said:
> 
> 
> > The support isn't really needed at the sides at all.
> ...


Shear strength of 4 - 3/8" lags is a heck of a lot more than the weight of 30 gallons of water.

If not for that, the concern would certainly be justified... The bottom tank, righ hand side sticks out too far for that 2X4 to go all the way to the floor. I would prefer that it did but had to have a way to remove that 30 BR without taking the whole thing down..


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## newforestrob (Feb 1, 2010)

I hear you,I should have been more detailed in my concern,you have both the top and middle tank's weight transferred to the hardware on the first vertical 2 bys from the floor,I am by no means a structural engineer :lol: 
it may all be fine :fish:


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## Rhinox (Sep 10, 2009)

*Number6*
I've been thinking all afternoon if there's something I'm overlooking. I've actually been tempted to put together a quick solid model and run an FEA  :lol:

*newforestrob*
Hardware can carry sheer loads. The screws I buy at home depot tell me what the sheer loading rating of the screws I use are. It is not wrong to have load carried through the fasteners if you understand and intend for it to happen, and design for it.

Maybe its just the dramatic shocked emoticon (  ) that gives me the impression that you think weight being supported by the sheer strengths of the fasteners means the end of the world 

Too many unsubstantiated thou shalt never/always statements are passed around the forums as absolute truths. Maybe I like to play devil's advocate sometimes. I would never recommend someone to setup a tank that wasn't properly supported, but I don't see justification for any disaster occuring (except for maybe the dresser failing). In the end the OP has to make up their own mind. If I were in a sitution where I had some emergency and I had to set up a 55g tank this second but the only place I could put it was a sturdy table 3" shorter than the length of the tank, I would not not even think twice or lose a minute of sleep over it. I don't ever anticipate being in that situation and would never set up a tank like that myself, but my opinion remains that it would not be a problem.


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## cantrell00 (Oct 30, 2010)

newforestrob said:


> I hear you,I should have been more detailed in my concern,you have both the top and middle tank's weight transferred to the hardware on the first vertical 2 bys from the floor,I am by no means a structural engineer :lol:
> it may all be fine :fish:


The concern seem well intentioned so by all means, we all can use all the help we can get.

Certainly there are better ways to design a stand and I will be the first to admit that this is not one of my better moments but given the weird geometry in that room and the overall lack of space - well, I had to make chicken salad out of uhmm .. well , you know... :lol:


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## newforestrob (Feb 1, 2010)

Ya,just trying to help,I loved your build,and it all turned out great,hope you are rewarded for all your efforts


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## cantrell00 (Oct 30, 2010)

newforestrob said:


> Ya,just trying to help,I loved your build,and it all turned out great,hope you are rewarded for all your efforts


I'm not done yet... :thumb:

It has been a blast. Anyone that loves these gilled creatures the way we do deserves their own room without all the compromises...

Thanks BTW.


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## coonie (May 23, 2011)

this dresser is old...and very well built and heavy.....it holding the weight isn't even worrying me...but the 50/50 responce here does....i dunno what to do...................................................


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## 13razorbackfan (Sep 28, 2011)

coonie said:


> this dresser is old...and very well built and heavy.....it holding the weight isn't even worrying me...but the 50/50 responce here does....i dunno what to do...................................................


Shoot All-Glass or Oceanic a email and see what they say. Call the owner of glass cages(I have dealt with him on several occasions including a tour of his facilities in tennessee)...he is very friendly.

I would not take a chance of flooding your room, ruining dresser, killing all your fish, etc..based on what some folks believe may or may not happen based in theory. I would however trust the manufacturers of these tanks and take them at their word as they know what they are talking about.

Ultimately it is up to you. All we can do is give advice. Like you said...it seems 50/50 and if you like those odds then go for it. I can see it working ok on a 30g maybe 40g but I think 55g is pushing it and certainly any bigger and it would be more of a problem.

If you do send them an email and they respond please post their response back here for future reference. If you want...I will shoot them an email or place the call tomorrow and report back what they say.


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## Steve C (Oct 9, 2011)

> I would not take a chance of flooding your room, ruining dresser, killing all your fish, etc..based on what some folks believe may or may not happen based in theory. I would however trust the manufacturers of these tanks and take them at their word as they know what they are talking about.


Same here....I'm by no means taking sides ...But this makes perfect sences to me!

Just my honest .02 cents


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## cantrell00 (Oct 30, 2010)

This illustrates my point well.... I honestly think you will be fine....


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## TCP (Jan 16, 2012)

newforestrob said:


> cantrell00 said:
> 
> 
> > The support isn't really needed at the sides at all.
> ...


+1 :wink:


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## tim_s (Nov 27, 2011)

1,5" of over hang will change the dynamic of the compressive forces.


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