I am new at this so I have been trying different methods. I had trouble with mold also from the environment being too moist. I also took cuttings of plants into flower and found these to be the ones that have developed mold the most. Still trying to see if I can get them to take. I have had luck in the Jiffy plugs which I think are peat. I tried coco, rockwool and pearlite with vermiculite. Same results with all, the high humidity caused mold in the flower cuttings and the others later. I also had them in separate containers. I have been misting the top of the tray now rather than misting the leaves. I just mist the plugs. Still waiting to see what they give but the coco has roots now.