I just got back from picking up a 150 gallon with stand. I set the stand up and it wobbles. I tried moving it around but it still wobbles the same amount. When I put the tank on the stand the tank sets flush to the stand but the whole thing wobbles. When i hold it to were it wouldnt wobble one corner is about an 1/8 of an inch off the ground. The stand is the one you would get in a petsore combo. I got this one off someone on craigslist. Should I go get some shims to put under that one corner or will I need a new stand?