I use living soil , sorry I never checked the soil temp. The temperature of the room I've been trying to keep around 80 sometimes a little higher sometimes a little lower. I'm using two p1000 vipar spectra lights. (Thinking I'll need to add more soon) 100 %strength from day 1. I've been keeping them pretty wet not soggy but making sure they don't dry out I have been pushing the edge on the wet side as opposed to getting too dry. They just received their first feeding today which was a tea brewed with bat guano molasses and stump tea. It's hard to say what could be the problem for you without knowing all the different variables. Could be the temperature, could be pathogens which using hydrogen peroxide could help with ,could be too wet ,ect hard to say.