Leveling Mat?

[BigJohnny]

Yes it has black trim around the bottom

I’m worried about in the middle it has a gap the ends are all ok it’s just the middle

Even if you are worried about the middle, a mat wouldnt do anything. In fact the only thing it would do is increase the risk of applying pressure to the bottom glass, which you dont want.

Ideally a rimmed aquarium should be supported all the way around the rim, with all 4 sides touching and level. Worst case all 4 corners need to be supported and level for standard tanks under 4 feet, which means some little gaps in the middle should not be an issue. I've seen people put 6 foot tanks like this but I wouldn't recommend it.

Have you filled the tank with water to see if the gaps are still there? Is your stand top flat/coplaner/level? A lot of times the tank will settle after filling. How big of a gap are we talking, like a couple mm? Are they on one side or two? Short sides or long sides.

This video may help:

 

[BigJohnny]

Yes it has black trim around the bottom

I’m worried about in the middle it has a gap the ends are all ok it’s just the middle

Foam/mats are for flat bottomed tanks with no rim to remove any possible pressure points from minor imperfections on the stands top surface.

 

[justingraham]

Foam/mats are for flat bottomed tanks with no rim to remove any possible pressure points from minor imperfections on the stands top surface.

The way I have it now no water

The gap

 

[revco33]

OK I’m resurrecting this.. I have a 75 gallon 48in long braced going on my DIY stand and want to use a yoga mat as a imperfection absorber the stand is perfectly level And over build all lfs say but preferred. So will it help take more pressure off the seems and I don’t know if the consensus was yes they do take away the imperfections well? Thanks. Here’s my stand sanding it. I took it on the way 2 lfs a few days ago

I see a lot of gaps between 2x4's. get those joints tight