I lost 1, but the second hatchling fully recovered that night. Something stunned those two and were unable to come up for air. They were in 10 inches of water. I removed the "turtle cliff", and now they're in one inch of water. I might put them in my 100 gal. terrarium with my gulf coast box hatchlings. So to recap; 1) Drop in temperature might have stunned them? 2) Held under by one of the suction (5 total) holes?