LECA ( Lightweight Expanded Clay Aggregate ) is becoming one of the most popular and versatile substances in horticulture. As a soil component or medium, it retains moisture while providing excellent drainage for excess water. Many of our customers use LECA in a clear container of vase and put node or leaf cuttings into the LECA and keep the container roughly 1/3 full of water to watch the propagation root quickly and know right away when it's ready for a real potting mix to continue to grow long-term! Also works well as a drainage layer in the bottom of a pot or as a soil topper for a unique desert or Martian theme!