Level of the tank

[swiftwing7]

I am trying to level my tank and was wondering how important the levelness of the tank is? How Perfect does it have to be? I am trying to figure out a way to level the tank by putting something under the stand. The foundation of the whole house is poured slightly off level so my stand is off and if I just leveled the tank it might be noticable that the sides arn't all parallel. When I use a bubble level on one side of the tank the bubble is close to the line. When I put it on other side it touches it, Is this that bad? The tank wouldn't have to move that much to fix it and I was wondering how crucial it is too fix it. I was thinking maybe a bit of thin cork under the stand. I already have a layer of cork around the top of the stand that the tank sits on. Its about 1/8 of an inch. Should I should just double it?
Thanks

 

[phases99]

Get it as close as possible. Fill 1/2 with water and check again. The cork may balance things out. The more out of balance the tank is the more likely you may get stress fractures over time.