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Very white fungus/mold on grow mediums

Discussion in 'Marijuana Plant Problems' started by blazechronj, Jan 3, 2009.


    blazechronj Active Member

    This is my first post, so I'll use the guidelines I found.

    2) Growing indoor or outdoors
    Growing indoors w/ AeroGrow Deluxe

    3) Watering schedule
    17 hours on / 7 hours off

    4) Growing Medium
    Sponge like (I'll attach a picture)

    5) What stage of growth
    Late vegetative; just began inducing flowering.

    I have excellent circulation and alot of fresh air.

    Temperature varies from 70 to 75.

    I'm keeping humidity from 5-10% until resolved.

    I know herb enthusiasts like to talk trash about the aerogrow, but these plants are growing incredibly fast and they seem happy as hell.

    So the biggest drawback I've found is the inability to manipulate the pump cycle since the pump and the lights run off the same power source.

    About two weeks into my grow, I started noticing a fluffy white looking mold on my grow mediums. The first thing I did was to eliminate all humidity and maintain constant airflow around the base of the plants. After a week of this, the fungus still continued to increase it's spread across all the growing mediums. At that point I decided to block all the light, which of course isn't working.

    I'm now 30 days into my grow and the only reference I can find to is in a CC thread where someone describes the same occurrence but notes that he had a successful harvest regardless. I also found the following:

    "White mold grows kinda like a fuzzy cotton ball on the clumps of the soil. If yours looks kinda like this then it is a moisture problem. Clean off by removing the top soil around it and along with it. let the top soil dry out for a couple of days, then proceed to water as you did before. If it comes back, try a different soil and or get better air circulation going around the plant. Most forms of mold don't grow in light to well if at all. More lighting can help."
    Vote 2 Legalize Marijuana on rollitup.org


    "On the top of the soil? Mold?

    Are you talking about nutrient salts that collect on the surface and dry to a powder-like stuff? If that's the case, it's nothing to worry about."

    Potroast on rollitup.org

    It's driving me insane trying to find some concrete explanation of this specific mold. I've done a lot of research and I know it's not fungus botrytis "grey mold" The white just appears on the growing mediums; I'm circulating/ventilation air like mad but it doesn't seem to want to spread anywhere on the plants themselves. Unless this is a marijuana specific organism (which I can't find a solid reference to), I doubt anyone would marken a hydro system that has such flaws.

    While this doesn't seem to inhibit my growth all that much, I have to assume that it thrives off of something in my nutrients or something in the air which my plants probably need.

    This is my first time growing so any constructive criticism will help; Again don't bother talking sh*t about the aerogrow, I got it as a present anyways so I didn't blow any money on it.

    All the pics attached are no older than 30 days of growth. (I have some deficiencies as well but I'm growing w/ custom fertilizers as opposed to the aerogrow "nutrient tabs" next grow so I'll focus on those later)

    Any idea what this white stuff is?

    (sorry this is so winded, just worried about my babies and I'd like some site to have a good reference of this for other growers)

    Attached Files:


    blazechronj Active Member

    Just found something on the Aerogrow website:

    There is white stuff growing on my Grow Sponges (or plants).

    Sometimes people notice a white fuzz developing on the surface of their Grow Sponges, especially when the plants are small. This may be a fungus that is decomposing any seeds left behind in the Grow Sponge that did not sprout.

    If your plants are still small, you can usually remove the dead seed by following this procedure:

    Remove the label (if you can) from the top of the pod by making a cut from the center to the edge of the label and gently peeling it off, being extremely careful not to cut or damage any little sprout stems. Save the label, as you can put it back in place like a collar later.

    Gently open the Grow Sponge and see if you can find any unsprouted seeds, and if you do, gently remove them with tweezers. Once the dead seed is removed, the fungus will die off.

    If you have a fungus that is starting to grow up the stem of a little plant, do the procedure above first as it is most likely the source of the problem, but in addition, dip a cotton swab in a bottle of hydrogen peroxide (available at any drug store or supermarket), and very gently daub the stem of the affected plant with it. This should kill any fungus.

    If the seed pod label was not stretched out of shape while removing it, you may reuse it by opening it and gently placing it back around the plant stems. As the plants grow, they will anchor the label in place. The label is important so that you can identify your plant, and also to prevent light from entering the Grow Sponge and causing algae to grow. Algae will not harm you or your plant, though people sometimes find it unsightly. If the seed pod label was damaged when you removed it, a small piece of aluminum foil can be cut to the same shape as the seed pod label and used in place of it.

    Looks like I found what I was looking for.

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