# Styrofoam or no?



## tyrone (Mar 20, 2003)

Two schoools of thought:

One says put the styrofoam the other says its no use :-?

How many of you use styrofoams under your tanks? Do I need to put it as I have just redone my 80 g which sprung a small leak on the bottom back corner some months ago. I can't decide whether to put the foam or not as I'm just gonna let the tank be bare bottom, no sand, rock or gravel etc. Was thinking maybe I should go without the foam and see how it goes but then I dont want 100s of gallons of water on my floor :-?

Thanks.


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## trigger (Sep 6, 2002)

One of my tanks does have it, two other don't. The two that don't are factory built Juwel tanks with their own supporting rim. You'd even void warranty by putting Styrofoam under them. The tank that does have Styrofoam is a custom built corner tank that rests on a metal frame with a wooden board on top.

I think the rule of thumb would be that if any other piece of the bottom than the edge is resting on something, you'd better use Styrofoam.If you have the tank in a rack with only the sides supported it's no use.

Basically the Styrofoam acts to even out small unevenness between the glass and the supporting thing, so no stress comes on the glass.


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## tyrone (Mar 20, 2003)

Hi Peter,

Well this one's a custom built 5 foot long on a metal stand with a wooden board on top, so I think I'll just play safe and keep the styrofoam beneath the tank.

Thanks


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## prov356 (Sep 20, 2006)

My only caution, and one I received from a tank manufacturer, is to make sure the foam is under the tank frame only and doesn't push up on the bottom glass.


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## trigger (Sep 6, 2002)

prov356 said:


> My only caution, and one I received from a tank manufacturer, is to make sure the foam is under the tank frame only and doesn't push up on the bottom glass.


If your tank rests on a frame, I'd leave the styrofoam out all together. Thats the case with the Juwel tank I described. These tanks rest on their own frame and should not be supported with styrofoam.


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## tyrone (Mar 20, 2003)

The only thing that worries me is the fact that the ground level is not even, so the result was that the stand was not level. I put some pieces of cardboard beneath the legs so that now its stopped shaking and the stand is steady.

Should I still put the styrofoam? It covers the whole board resting on the stand frame.


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## prov356 (Sep 20, 2006)

I'd use something besides cardboard. I would think that cardboard would crush over time and the stand
could twist. That could cause some serious stress on the tank. Wood shims are a better idea for 
leveling tanks. Wood shims can be purchased at home improvement stores pretty cheaply.

If the tank sits flat on the stand and is supported on the corners, then styrofoam isn't needed.

Re-read your post, and no, I wouldn't put styrofoam down that covered the whole tank bottom if there is 
any chance that it could push up on the bottom glass.


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## tyrone (Mar 20, 2003)

Thanks I think wood shims are a better idea. So dont put the styrofoam, just put the tank directly on the board resting on the stand frame?


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## prov356 (Sep 20, 2006)

> just put the tank directly on the board resting on the stand frame?


That's what I'd recommend, but that's based on having a proper stand. When you place the tank on the 
stand, it shouldn't wobble corner to corner. That's the most important thing. If it's a longer tank, and 
there are gaps along the long edge, then some support under those edges may be a good idea. But, 
best practice is good support on all corners and edges on a proper stand. At least the long edges. 
Short edges don't matter if there's a gap. And again, I'm restating what I was told by a tank 
manufacturer. He didn't qualify 'long' tank, but I'd say 5' probably qualifies.


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## tyrone (Mar 20, 2003)

> That's what I'd recommend, but that's based on having a proper stand.


Dont you think it would be safer to put the styrofoam then, just in case the stand is not pefect for supporting the tank? The reason I'm asking is I have an 80 g already running with styrofoam underneath.

The tank which was repaired also had a styrofoam sheet underneath. Two years ago it had developed a crack on the bottom glass, right across and as a resut, it drained out completely and we lost all our fish  Now that we're setting up this tank again, I'm soooo confused even though its only gonna be a bare bottom tank.


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## prov356 (Sep 20, 2006)

> The tank which was repaired also had a styrofoam sheet underneath. Two years ago it had developed a crack on the bottom glass, right across and as a resut, it drained out completely and we lost all our fish Sad Now that we're setting up this tank again, I'm soooo confused even though its only gonna be a bare bottom tank.


The foam may have cracked the bottom glass. That's why I wouldn't do that., and that's exactly what the 
tank manufacturer said might happen if you do that.

Get the tank on the stand and check it. Make sure it doesn't wobble corner to corner first. Then see if 
there are gaps under the long edges. If there are, then I'd take a thin (1/8th in) piece of foam that's 
about 1" by 6" and put it under the edge toward the middle of the tank. That'll give the middle some 
support. That's all I'd do, and that's only if there were no way to correct the stand so that the foam 
wouldn't be needed at all. If the 1/8" foam isn't thick enough to fill a gap, then I'd consider not using 
the stand. If you wanted to, you could make the piece longer so it rests under more of the edge, but I 
wouldn't go so long that it comes near the corners. Let the corners rest on the stand.

Hard to say exactly what you should do because I'm not standing in front of it. All I can do is make 
some general recommendations.


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## Sin in Style2 (Feb 6, 2004)

one long sheet of thin foam isnt gona cause a crack. the idea of foam is to limit imperfections. i use a crafting foam which has a thin paper on both sides. gives it a bit more rigidness.

Anyway the way it works is if there is a gap or unlevel part of the top of the stand where the frame of the tank meets this could cause strees. This point of preasure can cause cracks over time creating leaks. By using foam it makes these points spread out or nonexistent. Water naturally levels itself out and so will its weight. its the frame to surface points that are the issue.

With all that said i only use foam on my largst tank a 75g on a custom built stand. The surface of the stand is half inch plywoof stained and 3 coats of poly. Its as flat as your gona get but still not perfect. The foam is proly 1/16th of an inch thick if that. Only purpose was to create support where there was none and give where there was extra creating a level surface. 4 yrs have gone by without any issue at all.


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## prov356 (Sep 20, 2006)

> one long sheet of thin foam isnt gona cause a crack


As long as it's thin and doesn't push up on the bottom glass, no it won't. If it's not thin and pushes up on
the glass, it may. 'Thin' styrofoam can mean different things to different people. The key is whether it 
pushes up on the bottom glass. 1/16th like you used probably would not. Personally, I wouldn't risk it, 
since it's very easy to trim out. And again, I'm only re-stating what I was told by a tank manufacturer.

Went and found the exact quote regarding the use of foam:


> Tim,
> 
> Some people do it, but we do not recommend it on glass tanks. It is a good practice for acrylic tanks however. Just make sure it is on a level aquarium stand, and for the warrantyâ€™s sake on a stand approved by the aquariumâ€™s warranty.
> 
> ...


I asked him to elaborate on why it's not recommended and this was his response.



> Glass tanks technically only need support under the corners, but the longer the tank, the more
> support is needed along the length of the long edge. The underglass does not need any support.
> The glass is double pane on the bottom for strength. The Oceanic and All-Glass 6 foot tanks'
> bottoms can hold up to 10,000PSI, the 65, 75, and 90gal tanks can handle about 8000PSI.
> ...


I believe when he uses the term 'level' he means flat. I couldn't find the part about pushing up on the 
glass. That may have been in a thread on this forum somewhere, don't remember now.


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## mithesaint (Oct 31, 2006)

I think when he uses the term "level", he probably means "Level" AND "Flat". You can certainly have one without the other, and missing either the level or the flat part of the equation will certainly cause problems. I can have both sides of the stand level with respect to the horizontal plane, but that doesn't mean the top of the stand is necessarily flat. You need both.


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## Sin in Style2 (Feb 6, 2004)

I was referring to the outer edge of the tank frame. there is foam under the bottom glass but its a good deal away from it. the outer edge was the concern for my tank as i didnt want something like a bump in the wood in the middle part of the long edge. this would cause the outer edges to be pushed down from weight and crackign the center.

There is another bonus to styro thats usually forgotton. my stryo is one long peice under the entire tank flush with the stand NOT the bottom fo the glass. This causes an air pocket with insulation on the bottom. Would act just like a double pane of glass and keeping alot of heat from escaping through the bottom glass.

Anyway just thought i would clarify that it was not touching the bottom glass at all. was only used to further level where the frame itself was touching the stand top.


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