Tank not sitting flat--how to fix

Hi all.

My new (used) 55 gallon isn't sitting flat on my stand. It kind of rocks like it's warped on the bottom. I did fill up the tank and it held water for a several hours no problem. I know the stand is flat because the other 55 I had on it sat perfectly flat, so its definitely the new tank. The gap is on the back left half (barely visible) and the front left half (about 1/32"), so very small. What are my best options. Foam? Is there something else I could put under the gaps? Some thin material? Just want to make sure the tank sits flat on the corners. Shims are too big.

 

Well I would check the stand with a level to see if it curves to be sure... the old tank may have just been pressed into the shape of the stand. You could sand or whittle the shims down smaller. Any kind of rubber should work to help cushion the tank a little bit. I used some rubber type flooring under my 36 gallon tank because my home made wooden stand was slightly warped. I shimmed the top of the cabinet and then put the rubber down and there are no gaps.

 

I use metal shims. they're very thin

 

Where did you get this rubber flooring material? Could you be more specific of what it actually is?

Where can I buy metal shims? I googled it and couldn't find a place that sales them right off the bat.

 

I think I've solved my issue. I'm going to do a few layers of craft foam sheets. I will make thin sheets of it and "over" stack it to make it thicker than needed. It will settle with the weight but should fill such a small crack very nicely, probably with about three layers of it.

 

I wouldn't try to shim the sides of the tank. The only areas that need solid support are the corners. Place a small square of window glass (about one inch square) under each corner. This will lift the tank enough to relieve any stress along the sides which may lead to cracking or seal failure. Quarters work as well, but are a bit more visible. Foam will also work from what I've been told.

I was given this advice from a retiring LFS owner. He had used this method for many decades and reduced his number of broken leaking tanks tremendously. I've used this method on virtually all of my tanks over the years and have never had one break or leak. It's the uneven support along the sides/ends of the tank that are the problem when they stress the glass unevenly.

 

Yes, that is the plan. I'm going to support the two corners that are lifted with a nice thick layer of foam that should settle nicely. Buy I may also add the foam on the other gaps as well just to take as much stress off the tank as possible. Honestly, a 1/32" and smaller gaps isn't much, so it won't take much to fill it.

 

metal shims would be made out of a piece of 29gauge sheet metal

 

Hey everyone, thanks for the help. I actually decided to go with felt. It settles but not quite as much as foam. In the places where it was 1/32" off, I put two pieces of felt, and I put one piece of felt in the even smaller spaces.