In looking at the ADA Amazonia II Aquasoil (at Aquaforest Aquarium), I noticed that there is also a "powder" form of this product. Surely they mean more like "sand" than powder, right? Are there any advantages/disadvantages of the powder type? I don't mind spending a little more, if there would be some benefit. In the end, I expect my substrate to be completely covered with plants, i.e. there won't be bare substrate visible, so I'll take utility over aesthetics.