Leveling the top of a metal frame

[RobDob]

Hi,

This is my first post here, so thanks in advance for any help.

I have been keeping fish for many years and have now embarked on a project to setup my largest tank yet. The tank is a glass tank measuring 7' x 2'6" x 3'.

I have had a metal stand made by a family member. The problem is the metal stand has a slight bow on the top at the front, so with the tank on the stand there is a gap between the tank and stand at each of the front corners, one is about 5mm and the other is 3mm. The tank is currently sat on a 12mm piece of polystyrene foam and there is a 12mm piece of plywood between the foam and tank - I have not put any water in yet as I am concerned about the gap.

What I need to do is make the top level, the bottom is level on the floor.

My current thinking is to box the top in and lay a slab of self levelling concrete so that I get a perfectly level top and then place foam between that and the tank.

Does this sound like a good idea? Has anyone else had this problem? Any better ideas? I'm open to any suggestion.

Thanks,

Rob

 

[Pharaoh]

You have a picture?

Is the gap specifically at the corners or just near the corners?

Does your tank have plastic trim on it?

 

[RobDob]

Yes its actually at the corners, this is what has me concerned. Here is a picture:



The tank does not have a plastic trim, its a flat glass bottom.

Thanks.

 

[Dan F]

The self-leveling concrete is an interesting idea, but I think a bunch of shims would work as well and be much easier.

 

[RobDob]

I'm not sure shimming between the tank and the stand is a good idea - everything i have read says you will be simply moving the pressure point.

I have contemplated turning the stand upside down and shimming between the floor and the tank - the stand however was designed to stand one way.

All in the tanks and water are going to weight about 2000kg, so its a lot of weight....

 

[wednesday13]

I shim all my tanks under the tank between the stand and under the stand to the floor. My tanks are also all acrylic though, not positive on how this will affect a glass tank. Imo its better to try to shim than just leave it alone. I think ud be fine to throw down a piece of wood under the tank then shim under that piece of wood rather than from the floor.

Sent from my SAMSUNG-SGH-I747 using MonsterAquariaNetwork App

 

[RobDob]

The tank manufacturer said shimming between the tank and stand was not a good idea - that was my first thought.

My understanding is that acrylic flexes more than glass, its a very big piece of glass with lots of water so I'm somewhat concerned. It was hard enough convincing the wife it was a good idea to get it, if it springs a leak she is likely to go crazy

 

[Pharaoh]

I've shimmed stands between the tank and stand multiple times. You are spreading the pressure if done correctly. If you shim it too much then yes, you are changing the pressure points.

 

[Dan F]

I would place the shims next to each other wherever you can fit one in to form a more-or-less continuous support under any spots where the plywood doesn't touch steel. As long as you use a consistent amount of force (very little) to push in the shims you shouldn't have problems with too much pressure in one spot.

 

[jsodwi]

If that was mine and I was stuck using that stand, I would get heavier plywood for the top.5/8" or 3/4"And shim all areas that need it. And get the heavier foam as well.
If your guy is close that made the stand, have him redo the top. Most likely it wasn't constructed properly and warped when welded