Hydro Clay Pebbles (Leca Stones) Orchid/Hydroponic Grow Media - 2 lbs by PowerGrow Systems Perfect as a Hydroponic, Aquaponic, or general growing medium pH Neutral and inert and certified for Agricultural use Also great for Orchids and decoration Package of 2 LBS. Clay Pebbles provides excellent aeration and water retention Once of the time tested and most widely used growing medium.