Concrete backer board alternatives

[Spawn]

I was looking at using concrete backer board in my pond setup but i heard that it is toxic to fish, so i was wondering if there is any alternatives to this material.

 

[lapin]

I would think once you coat it with plaster it should be fine.
If its not sealed with something like plaster the pond will leak

 

[Spawn]

I would think once you coat it with plaster it should be fine.
If its not sealed with something like plaster the pond will leak

I thought that might be a solution. thanks

 

[Rmckoy]

Essentially .. it’s mortar but I believe it will have hardening agents , along with might have steel mesh inside ?

what about sculpting out of the same mortar for aqua scapes ?

 

[ca1ore]

Most concrete backer board isn’t water proof so of course you’d need to seal it with a waterproofing membrane. At that point doesn’t matter what’s in it.