I would not use that type of sand for a frog or non-desert dwelling toad (spadefoot).
Those fine particles can get into their eyes since toads tend to dig themselves fully under the substrate, it can also get into their air ways since they breath while under substrate.
If you do go with sand, I'd suggest 50% play sand with a 50% mix of that coconut block substrate, damp enough where it clumps in your hand. Play sand tends to be of a larger grade and from my experience raising toads since a child has never caused them any issues even when fully submerged.