[rastaangel]

I have always used plate steel for shims. Any metal shop can cut you some from scrapes.
When I leveled my 90g I filled it up 4" to level the water line cuz the plastic top might not be level right. I then shoved a small pry bar under it and lifted and slide the steel under. Filled it half way and checked again. Filled it just below rim and checked again. This winter I had to relevel my tank from the screwy winter we had. I just drained 10g off to see the water line and got my bro to use a small prybar under it so I could get a bigger one under the stand to lift it another 3/16" then put thicker steel shim in