LF: 5' x 2' piece of foam. Gvrd

[catgoldfish]

I really think a layer of self leveling concrete is over doing it. Just use shims. If you dont like wooden ones you can buy the composite ones so if they get wet they won't rot. It's just for a sump you're not putting in a new floor.

[smokinreefer]

Gotcha...
I have some shims already so I guess I'll just go that route.

The sump is 5' x 2' and trimless but with the plywood panel fixed to the bottom pane. So I was just worried about the tank sitting on shims on the edges but the center area of the tank not being supported by anything.