Grey Mold

Hello everyone. Yesterday i got home from work to check on my babies to see if they needed water well upon watering them i noticed my last plant in the back row (Chocolate Rain) has grey mold growing off the soils surface . I wouldnt mind the mold if it didnt kill my plant after time or made my smoke trippier feeling but it doesnt serve a purpose but contaminating my other plants. Well what i did was deroot the plant SOAK the roots in room temp water for 5seconds then slowly rinsed the roots off and rest of the lower part of the plant that were near the mold then soaked all old pots in bleached water to kill the mold then put the rinsed off plant in a NEW pot with new soil. My question is, Is there an easier way to kill the mold? The plant seems to be ok 8hrs after but I dont want to risk killing it or another in the future is the damn mold comes back.

remove any damaged leaves by cutting them off, wipe gently to remove some mold with a damp warm rag, invest in a air purifier and a dehumidifier if you can afford it. filtered intake is a good way to prevent mildew spores from resting in your grow space.

Thanks. I am very new to this so I wasnt really sure what to do. Only thing I could think of doing was de-pot the plant wash away all the dirt from the root, and put and in a new pot with new soil. I bleached the old pot and washed very well.

Is there anything i can spray on the top layer of the soil that will help prevent mold but be safe for my plants?

that grey shit in the soil is fungus gnat eggs.

You might have a fungus like Powdery mildew or Downy mildew. Spore can spread to other plants quickly. A product like seranade will work. Remove plants from grow room, clean grow room to remove left over spores. Then put treated plants back in the grow room. Use it once a week til the problem goes away. Also Pyrethrin fogger Bomb will kill any thing moving.