Mat under a rimmed tank?

[Zelly]

Thanks for the comments everyone

 

[Erokster73]

Thanks for the comments everyone

What did you end up doing? I just thought I finished up mine but now I see I have two areas about 6" long under the side of the rim that has a bout a .012" gap. All corners are good and atleast 80% of the sides. Thinking I may just tape some shims cleanly under the main parts

 

[EeyoreIsMySpiritAnimal]

What did you end up doing? I just thought I finished up mine but now I see I have two areas about 6" long under the side of the rim that has a bout a .012" gap. All corners are good and atleast 80% of the sides. Thinking I may just tape some shims cleanly under the main parts

Shims are definitely the way to go

 

[BeanAnimal]

@Zelly

A foam mat is NOT for this kind of "leveling". It's used on a trimless tank between the glass and stand to prevent any small imperfections on the stand top from creating stress points on the bottom (glass) of the tank.

For your problem, either correct the top of the stand or use shims.

*As long as the corners of the tank are fully supported (along with the majority of the edges), the small gaps between trim and stand should not be an issue, but since you have the opportunity to do things right, I'd recommend making sure the stand top is completely flat.

Alleviating point load on a trimmed stand is similar. The issue becomes selecting the proper foam.

Ideally you want one that will fully compress for the bulk of the perimeter and therefore support the gaps and allow no further movement. The issue here is that it can’t handle acute point loads.

Otherwise something stiff enough that it will barely compress, but pick up some of the weight along gaps and handle any acute point loads.

The issue, and why we don’t usually recommend a pad or foam under bottom trimmed tanks is that anything in between will allow the tank to become unstable and likely create more seam stress than it alleviates.

Regardless of the tank type, a non planar stand top is bad news and foam typically will not fix the issue.

 

[BeanAnimal]

Shims are definitely the way to go

What did you end up doing? I just thought I finished up mine but now I see I have two areas about 6" long under the side of the rim that has a bout a .012" gap. All corners are good and atleast 80% of the sides. Thinking I may just tape some shims cleanly under the main parts

Don’t worry about 6” of unsupported tank, especially of 80% of the perimeter is supported.

I am also going to adamantly disagree with the advice to use shims, you don’t need them in this case, but they really should never be used…

Do NOT use shims, especially not wooden ones, they can swell and cause point loads. Even composite may create an issue (point load) as the stand itself expands and contracts with humidity, spills, etc. Never use shims directly between a tank and a stand, never.

 

[67champ]

I have the same question, (same size tank) but sitting on an Amazon "aquarium stand" that I purchased and assembled. I cannot tell in O.P. photo how much the gap his setup had; but mine is probably less than twenty thousandths of an inch basically for about an 18-inch span where the front and rear bottom frame "should" be touching the aquarium's top surface. Like the aquarium stand's top is bowed in the middle. And, if it was anything else to sit on it, it wouldn't matter. LOL. I'm thinking of sliding several pieces of construction paper under the offending areas and that may act as a shim. Thoughts?