Tanks that hang off the edge of their shelves - is this okay?

[Gastroplod]

Hi all, I've seen a few pics of people doing stuff like this - and I'm interested to know what the general consensus is in terms of long-term safety. I have a 16g tank that I would ideally like position like that on my rack, and it would only overhang buy maybe 2-3 inches. these ones in the above image look like they are on some pretty hefty stiff insulation foam, which I have - but is this considered okay to do? Thanks 🙂

[Chris]

I wouldn't recommend it - the peace of mind of having the tank supported properly would keep me from trying such a tank. 

It'd be easy enough to solve the issue, though - supporting the tank with some lumber or plywood would probably keep it pretty safe. 

Is the tank glass? Rimmed? Rimmed tanks are more forgiving, although I'd still support them well. 

[TOtrees]

I think a small amount of overhang would be okay, but I couldn't say how much might be too much.

Safest would be no overlap, just to establish a bookend.

Tanks really are an "ankle bone connected to shin bone, connected to knee, connected to thigh..." sort of construct. Assuming all the silicone beads and seals are strong and intact, the "end" of the tank (the part sticking out in pics) isn't supported by the plastic frame, so much as by its connection to the two side panels, and the floor. The frame distributes weight, more than it hold things together (in the case of the upper frame however, it also helps keep the 4 sides from spreading apart, and stressing the corner joints). So the edge of the shelf, right where it's under the frame about 2" or so from the end of the tank, that would normally put a lot of point pressure on the bottom of the tank, including the bottom of the side walls. but the plastic frame distributes that point load or pressure lengthwise along the tank edge. However, the more the tank hangs over the edge, the more that point pressure at the shelf is, and the harder the frame has to work to spread that pressure out. 

Other than above, the question is how much bending occurs (or wants to occur) due to the overhang? What resists that bending is the vertical side panels. The taller they are, the harder is would be for it to bend or curve. In terms of physics (the general principles, not the numbers), tiny overhang = tiny bending/stresses. That's probably fine. More overhang = more stresses. I couldn't go beyond that.

 

[lefty o]

its not a good idea.

[TJ _isme]

I have never done this but this could stress the glass which could lead to it snapping apart and then you got tons of water flooding your house

[Tony s]

I’d be too afraid it would fail eventually. Figure 10 lbs per gallon with substrate and plants. Even a 20 is close to 200 lbs. just a ton of weight on a 40+ tank. 10 or 20 makes me less nervous though. 
 

and location is also key. If it’s in a garage or other spot where you don’t care if it cracks. By all means, go for it if you want to. In a living room. Yeah. Ain’t no way 

[Gastroplod]

Thanks for the replies. It does beg the question how often these things would actually break, because I'm always amazed that you can put a big tank on a frame that doesn't have a solid base. So there must be a lot of physics happening in the glass. Maybe having a stout bit of wood under the entire tank that itself hangs over is enough to spread the weight and pressure. It's really hard to know sometimes what's actually worth worrying about, and what's just being overly fussy with fishkeeping. I appreciate the input 🙂

[Tony s]

On 5/16/2024 at 10:06 AM, Gastroplod said:

what's actually worth worrying about, and what's just being overly fussy with fishkeeping

Probably a great deal of that. But we’re also smart enough to take no chances. Even a tiny chance at a crack could cause serious damage. Even 10g cleanup is going to be a pain 😂

[lefty o]

On 5/16/2024 at 9:06 AM, Gastroplod said:

Thanks for the replies. It does beg the question how often these things would actually break, because I'm always amazed that you can put a big tank on a frame that doesn't have a solid base. So there must be a lot of physics happening in the glass. Maybe having a stout bit of wood under the entire tank that itself hangs over is enough to spread the weight and pressure. It's really hard to know sometimes what's actually worth worrying about, and what's just being overly fussy with fishkeeping. I appreciate the input 🙂

it depends how/where the weight is loaded. you can support just the ends, or just the sides, but as shown in your pics just supported in the middle puts forces on the tank that can cause the joints to fail.

[Pepere]

On 5/16/2024 at 10:06 AM, Gastroplod said:

It's really hard to know sometimes what's actually worth worrying about, and what's just being overly fussy with fishkeeping.

I don’t wish to have experiential knowledge.

I had 1, 10 gallon tank fail catastrophically.  That was enough for me.  Significant time spent mopping up…. I don’t want a repeat.

It is easy enough in my book to build a rack able to fully support the entire tank.

Edited May 17 by Pepere

[Gastroplod]

Agreed, I don't want to have a tank leak/explode on me. Well this is a pretty ringing consensus of "no, don't do that" - so i won't be doing it either 🙂

[johnnyxxl]

On 5/16/2024 at 7:53 AM, Gastroplod said:

Hi all, I've seen a few pics of people doing stuff like this - and I'm interested to know what the general consensus is in terms of long-term safety. I have a 16g tank that I would ideally like position like that on my rack, and it would only overhang buy maybe 2-3 inches. these ones in the above image look like they are on some pretty hefty stiff insulation foam, which I have - but is this considered okay to do? Thanks 🙂

When I was super young my first tank hung over by an inch or so it was rimmed.  That tank was fine for years.  I wouldn't do it again, because that adds another area for failure.  I'm also aware we see everyone doing something crazy online, makes tempting fate easier.