Eggcrate Under Sand ?

[Dearth]

Depending on water flow you could potentially have egg crate show through as the sand is moved around by currents and critters I have egg crate on the entire bottom of my tank and I would rather have that extra layer of protection and maybe some egg crate showing than a cracked or broken tank. As to critter impediment I don't believe there will be an issue there.

[Aquattro]

Originally Posted by Dearth

I would rather have that extra layer of protection and maybe some egg crate showing than a cracked or broken tank..

Unless you're tossing rocks around in the tank, it's not going to break. Even if you tossed them, they'd have to hit hard.