Fungus gnats & thrips problem

Discussion in 'Growing Marijuana Indoors' started by Anavictoria, Oct 9, 2022.

  1. Hello, guys,

    I m once again asking for your help regarding a infestation we don t know how to deal with. I m talking about fungus gnats and thrips.
    We are growing in a hydroponic system (pebbles) and now the girls are in their late veg stage. Lately we noticed this infestation I told you about. We tried to get rid of them using a chemical insecticide and it was a bad decision, as the leaves got burnt. They are slowly recovering.

    We are really looking for an organic solution in order to minimize the "bugs".

    Let me know if you know some.

    Thanks a lot! Cheers
  2. Mosquito Dunks or Bits for the Fungal Gnats.

    • Agree Agree x 1
  3. Thrips can be difficult to treat since they lay their eggs inside the vegetative material. You will need to use potassium salts of fatty acids (ie. insecticidal soap, aka. hand soap) and some pythyrin. I also use neem oil. I found that regular treatment with Safer's EndAll with a tablespoon of organic neem oil added during the mixing up works well. You need to do this when the lights are off or it will burn your plants, and it may still burn some leaves. I really do not like to apply during flowering cycle as this will definitely burn the pistils out and nothing should be sprayed on plants during flower... but if its the first or second week of flower, I've done it. Just spray water to rinse after a week or so of insectide application. You need to reapply every few days to make sure to kill the newborn before they also lay more eggs. Takes a couple weeks.
    Also, what BNW said. I use mosquito dunks, but I place them in reusable tea bags and place them in the reservoir. This you can do throughout the entire grow.
  4. Try this @ 1ml per gallon of water in your resi. Add this you your feed at 1/2 strength or just with plain water for a week then swap and clean use for 2-3 weeks until dead IMG_4760.JPG

    Sent from my iPhone using Grasscity Forum

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