Foam under plywood tank

[salty55]

Im in the process of building a plywood tank that is 4'x8' that will be approximately 450 gallons. It will be setting on a 2x6 stand. Does everyone use foam under the plywood tanks like they do witch acrylic tanks? I'm kinda going between using the 1/2 inch sheets of foam sheathing, or at least the thin stuff that comes in rolls that you seal under stud walls with.

 

[pisanoal]

I wouldn't think it would be required, but it would serve the same purpose of leveling small imperfections and removing stress points. I wouldn't use the real thin stuff though, 1/2" at least and go with the softer stuff, not the super dense kind.

 

[salty55]

Yes! Reducing stress points is definitely what I’m after. There’s no such thing as straight lumber...