I bought this sand from a department store,I thought it was silica when I bought it.But when I got home I noticed the sign said it was hort sand.And I want to know if hort sand is okay with fish,plants,and invertebrates.
It should be OK so long as it has no organic matter or fertilizers added, or any of those little bits of styrofoam mixed in with it. I'm sure it's even pre-sterilized, which would be a plus. Is there any info written on the bag?
Horticultural sand is "sharp" as this is desirable when amending soil, but AFAIK that is the only difference. I guess if you have fish that root through the sand and spit it around it might not be the best thing for them, but otherwise it should be fine.