Using sand or Calci-Sand as substrate is dangerously harmful to a Geckos life. It not only dehydrates the reptile but it impacts them leading to a long miserable death. Leopard geckos can't digest Sand or Calci-Sand, so it basically constipates them to death. Petcos nation wide are disregarding their geckos health and well being and placing Leo's on sand. It's time to make a difference and a big one! Help geckos take a stand and stop Petco's policy of using sand!