Sounds like we have the same problem, 3/5 of my plants died about a week ago but two did good and this morning they were just dead so 5/5 are dead now. I have no idea what the problem is, i also have a small 6 inch fan plowing on the little guys the temp is running about 82 to 88 deg is not easy to stay at a good temp when it is 115 deg outside the light is about 18 inch away from the plants so there is no way that they could burn and I water every 3 days. Maybe it is the mirical grow soil. please help me that way I do not make the same mistake again.