Styrofoam and cement aquarium?

[Galactik]

Just stumbled upon these videos and was wondering if anyone here has done anything similar or if even it is something viable for like a backyard project?

I'm just wondering about how strong it ends up being or whenever the foam give out over time?

Looks pretty cool tho

 

[kingthedog]

cool tank

 

[riuqlav]

I was Wondering it too, even thinking about maybe it reinforced with wood maybe?