Day 4 of seedling stage and first I did my usual seedling mix with Pro Mix HP with 25% worm castings. We also have a personal fan in the germ kit so we donāt run into any mold issues. If you wanna keep the humidity up, just spray the tray and the heat from the heat mat is gonna create the humidity you need. As long as you keep it at 55% and above youāre good.