Gnats and larvae in marijuana soil

A question from a fellow grower:

I noticed these little
gnats around and tried to keep them under control, but lately I’ve noticed more and more. I read your website about
the gnats and their larvae. After checking the soil, I observed larvae all throughout the soil. I started treating the soil with
the peroxide/water mixture, but I’m afraid I may have waited a little too late to be proactive. My questions is: Is it suggested I continue to treat the soil or is it possible to transplant the plants into clean soil without sending them into shock.

Gnats in the soil is often a symptom of over watering. Letting the soil more properly dry out will lower the number of gnats significantly. Be careful to not let it dry out so much you kill your roots though. In general the top few centimeters of the soil should feel pretty dry to the touch and the container should feel noticeably lighter before you want water.

You can spread food grade diatomaceous earth on the surface of the soil and get a bunch of yellow sticky traps and or sticky fly ribbons and this will get the rest of them.

I agree; I would dust the soil with Food Grade Codex DE “DE” scratches the soft shelled insect and it dies from dehydration. When eggs hatch…same fate.

Guys , I have a couple dumb questions about the DE.

  1. When you say “dust” do you mean lightly or heavy enough that you cover the soil completely ?
  2. Do you remove this before you water/feed them again, or just let it dissolve into the soil ?