[TAB]

Anyone every use it as part of a mix for a substrate?

 

[SueNH]

I never used it for substrate but I do have a slab of rock in the tank with no problems.
Stuff is kind of sharp. I'd use something smoother.

 

[davemonkey]

I don't think it would be good to use it with bottom dwelling fish or fish that like to burrow due to it's 'sharpness'.

-Dave

 

[Quetzalcoatl]

Granite is chemically stable so it will not have any effect on your water. However, as others said, it is sharp and may damage your plant/shrimp/fish whatever you have.