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Discussion Starter · #1 ·
I just purchased a used 7' long 200 gallon glass tank. The top of the homemade stand that came with it is Styrofoam. It doesn't look good around the edges of the tank where the tank sits, but the rest of the stand looks good. The guy I bought it from said the weight was too great not to have the Styrofoam under it. Has anyone heard of this before? Could plywood under the bottom pane inside the trim be a comparable alternative? Any thoughts to make this look better are appreciated.

Thanks
 

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Post a pic of the stand, especially the top section where the tank will set.

If the tank has the stock plastic trim on the bottom portion of the tank there is no need to use styrofoam so I would ditch it. You could always attach a piece of plywood to the stand top but first I'd prefer to see a picture of the construction.

FWIW, I have a 15+ year old Perfecto 220G tank on the original stand, no styro, no plywood; the tank perimeter rests on the inside perimeter of the stand.
 

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Agree, the Styrofoam adds no support to the weight of the tank. The stand should be made (by the person who built it) strong enough to hold tank and water period. Deeda will be able to tell from a pic. May need to open the doors and show the supports inside under the corners of the tank.
 

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Discussion Starter · #5 ·
I think the idea is the bottom trim sinks into the styrofoam and the styrofoam under the bottom pane supports the glass from bending under the weight of the water and gravel.
 

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I looked at your pic and can't really tell how the top of the stand looks like under the styro. It would be better for you to remove the tank and the styro to get a better idea of how the top of the stand looks.

The other thing is that looking at the pic, the tank is either pushed over to the left to show the styro or the tank is shorter in length than the stand.

You do NOT want any material contacting the bottom glass pane of a tank that is manufactured with the plastic trim. The majority if not all commercially made aquariums in the USA with molded plastic trim are meant to be supported on the edges of the tank.
 

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01722 said:
I think the idea is the bottom trim sinks into the styrofoam and the styrofoam under the bottom pane supports the glass from bending under the weight of the water and gravel.
No.

Here's the deal ... it will require just a short geometry lesson.

A plane is a flat surface.

All planes which are defined by only three points are inherently flat ... it is impossible for it to be otherwise. All points are said to be co-planar (residing on the same plane)

Now think about the "plane" that is the top of the stand.

It is defined by four points, which bound the perimeter of the top.

If one of those points is not on the same plane as the other three, the top is no longer flat, but rather is twisted.

In the engineering, construction, fabrication trades the surface would be said to be "racked" (aka twisted)

The purpose the styrofoam serves is, by being compressible, it adjusts itself to conform to both the top of the stand - and - the bottom of the tank. The bottom of the tank - being rigid - is incapable of doing this by itself.

FWIW, I use styro underneath all my tanks for the above reason. (It also serves as insulation and mitigates heat loss or gain)

Can you get away without using it ?

Assuming a well-constructed stand, sure ... most of the time.
 

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Be careful to read your warranty...I know my lifetime full replacement warranty for my Aqueon tanks are void if I have anything under the tank touching something other than the frame.
 

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Discussion Starter · #9 ·
This is an old tank that definitely isn't under any warrantee anymore. The top of the stand is probably 1.5" wider than the tank and about 3" deeper. The styrofoam is unsightly for sure. I had filled it up and checked it for leaks prior to my original posting and it seemed fine. I'd just like to replace the top with plain plywood and trim it out if possible.
 

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If the top of the stand is flat, you don't need styrofoam. I use styrofoam on all my tanks and I built all my stands. Oh yes, I'm a carpenter. ;)
 

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If you look at the history of the all glass tank, the idea of using silicone to build a frameless tank, came from a local who was using the sealant in his work. This was in the late 50s. Crystal Aquarium was formed and they started to build tanks. The first problem they encountered was with the bottoms breaking. The cause was a point load caused (usually) by a single or few grains of gravel on the stand the tank was set on. So, they added a frame on the bottom to lift the bottom pane up. That fixed that problem.
There is no reason not to have the entire bottom pane supported, as in an acrylic tank. The potential problem is when the bottom support is not flat and/resilient. If you have the four corners of a stand in the same plane (as mentioned above), the tank will be supported evenly provided there is no upward protrusion anywhere else on the top support frame. This where styro comes in. It can absorb minor deviations in flatness provided it is soft enough. This will do the same for a rimmed tank. The tank is essentially a box beam. It is a very strong structure that can, in fact, be supported only on the ends. There are reasons not to do this, of course, such as adding unnecessary strain to the structure. It is much better if the the silcone only has to resist strain in one direction. It is understandable that a manufacturer would specify how their tank is supported to validate the warranty. It is really the only way they have of controlling what happens to their product when it leaves their facility.
I have four steel stands I built a number of years ago. In spite of the careful selection of the tubing, and in one of them angles, after they were welded there were slight curves on the long sections caused by the welds pulling. Two of the stands have two, four foot long, frameless 30s, each, that I built, on them. The centre portion of the tanks didn't touch so I added 1" of styro. This protects the glass because there is no bottom frame, but, the white styro compressed where necessary to fill the small gap and evenly support the entire perimeter of the tanks. I built the stands and tanks in 1992.Wood unlike steel, will move and as the humidity changes at various times of the year. This is normally not an issue. This is one of the reasons for the use of MDF in commercial stands. Aside from lower cost, it is more stable.
I did have one 15 I set up a number of years ago where I supported the bottom rather than the rim. The reason I did that was because I had a wall of loose rocks across the entire back. The styro would keep the bottom glass from flexing should a rock fall on it. If glass can't flex it doesn't usually break.
Bottom line is, that if you provide a flat surface for the edges and prevent flexing of the tank, it shouldn't break
 

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I have had a 75g tank that was given to me a year ago. I never set it up, because I did not think I could build a stand with a perfectly flat top. And, I live in a mobile home that was manufactured in 1972, so the floor may not be completely flat. Even a store bought stand would settLe to the floor over time and then be twisted.
Imagine that one corner of your stand is an 1/8" lower than the other three. The one corner of your tank would be suspended in the air with over a thousand pounds of water trying to twist the glass to rest on the surface 1/8" below it. The odds are that over time the seal will give and start to leak. I have a 55g tank (also given to me) that has a small leak for that reason and it was on the stand that came with it. The floor was uneven. Just last month I saw for the first time an aquarium sitting on foam. It is GAME ON NOW!
I purchased wood yesterday and construction of two stand will start this weekend.
I bought black packing tape on Amazon and plan to cover the edges of the foam to dress it up.
I will post pictures one day as my project goes on.
My two non-cents worth.
 

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A note about how the foam helps. If you have one corner that is 1/8" above the stand top because it is twisted, the corners (and edges between them) will have all the weight on them and the foam will compress. As those corners press into the foam, the corner that was suspended will sink down into the foam as the other corners do. Eventually the weight of all four edges will be equally transferred through the foam and onto the stand.
I hope that makes sense...
 

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johnnymax said:
A note about how the foam helps. If you have one corner that is 1/8" above the stand top because it is twisted, the corners (and edges between them) will have all the weight on them and the foam will compress. As those corners press into the foam, the corner that was suspended will sink down into the foam as the other corners do. Eventually the weight of all four edges will be equally transferred through the foam and onto the stand.
I hope that makes sense...
Keep in mind that if you use high density foam, ie: stryrofoam SM (the blue or pink stuff), the tank will barely sink into it no matter what.
If you are going to use foam, use an open cell type.
 

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Take the point of your finger and press it into high density foam. It will press into it with 10 pounds of pressure. Now take the frame of a tank, 48 inches long and a quarter of an inch wiDE with 400 pounds of pressure on it.... it will comprrss... just saying.
 

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johnnymax said:
Take the point of your finger and press it into high density foam. It will press into it with 10 pounds of pressure. Now take the frame of a tank, 48 inches long and a quarter of an inch wiDE with 400 pounds of pressure on it.... it will comprrss... just saying.
I have a 210g tank on 1/2" styrofoam sm that has not pressed into the foam at all in the ten years it's been sitting on it. Probably has something to do with the weight being distributed over a greater area than the tip of your finger.
 

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noddy said:
I have a 210g tank on 1/2" styrofoam sm that has not pressed into the foam at all in the ten years it's been sitting on it. Probably has something to do with the weight being distributed over a greater area than the tip of your finger.
True That!
 
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