Unlevel floor

[vfrstephen]

I have just got a 55 gallon and the floor i am puting it on is unlevel at one end by at least 10mm the floor covering is heavy duty carpet and foam underneath.

What you i use to level the tank out ,cement sheeting ok? or will it crack any ideas? thanks,
Stephen.

 

[FishNCash]

Tile, concrete blocks, wood. Anything that is not brittle under heavy weight.