Sand

[JP457]

would masons sand would work as a substrate? It is fairly coarse so I bought some to try.

 

[Decz]

i'm not sure what kind of sand it is that you are refering to, but, what I would do is, is to put some in a bucket, and monitor the PH, KH etc. GIve it at least a week, and see what happens. if there is no change, then it should be good to go!