What can cover my Foam Background with?

[Slowbro]

I see people using Coconut Fiber to cover their foam backgrounds in terrariums but that would fall apart in an aquarium. What do you recommend I use with silicone to cover the foam with and give it a better look that won't fall off?

 

[SludgeMunkey]

I see people using Coconut Fiber to cover their foam backgrounds in terrariums but that would fall apart in an aquarium. What do you recommend I use with silicone to cover the foam with and give it a better look that won't fall off?

Hydraulic cement.

 

[minxytota]

Drylok paint for concrete floors is what I use on my Styrofoam backgrounds