Habitat - Indoor :: Unlevel Aquarium - Shim Methods?

[ChangTang]

I have the 55 gallon on 3 stacks of 3 concrete blocks, with 2x4's and a 3/4" MDF sheet spanning the area. The horizontal alignment of the aquarium is level, but the front to back alignment is not. What would be the best shim to place under the stand in the front so it would be even. I was thinking of using some thin 1/8" plywood and put a small square under the front of each leg, but then I got to thinking of foam, possibly putting a layer of foam underneath the front of the legs? What should I do to make the tank perfectly level? It's not that big of a difference, but I want it to be as safe as possible.

[PridgNYC]

I used these on my wife's wardrobe cabinet. They are wedge shaped and black plastic, with break points built in, so you just shove it under far enough to level it and break off the excess.

http://www.acehardware.com/product/index.jsp?productId=2720228&kw=shims&searchId=53247487064

[ChangTang]

I already figured it out. hahaha. I was hoping to get an answer before i started but oh well. I just cut a 1" strip of 1/8" plywood and ran it along the front under the 2x4's and voila! the tank is filled and the filters running! today was a successful day.