Has anybody used the expanding foam..."great stuff" for building aquarium decorations. etc...?? I'm designing a custom 8' long river tank ecosystem for our nature center, and I need to build up the bottom/slope.

Is this stuff safe to use for fish after it is cured?

If so, will it be ok continually submerged (I know it will want to float....got that figured out already)

Any other suggestions?

Thanks...ECO