I bought this sand waterfall online and it didn't come with any instructions, just a little packet of sand. I can't get this to work....... I put the sand in the basin and nothing happened, I got maybe a few small particles to come out of the lions mouth. I then put some sand in the hole you see in the brick wall and nothing. I have an air pump rated for up to 30 gallons, which is what the tank is. I thought maybe the pump was too weak so I put an air line splitter on and attached another pump. That did increase the air flow but very very little improvement. Any ideas? Does my whole substrate have to be sand for this to work? The bottom of the ornament is solid, there's just air airline barb on the outside corner.