For fungus gnats we use MICROBE-LIFT BMC Biological Mosquito Control as a root drench. To prevent them: 0.1 mL per gallon OR 1–2 drops per gallon. For a light infestation: 2.5–5 mL per gallon. For a heavy infestation: 10–20 mL per gallon for the first drench. Don't run it with bleach, HOCl or any other sterilizer.
We've used these rates in our gardens for more than two decades.
Prevention and treatment rates
| Use | Amount per US gallon of water |
|---|---|
| Prevention | 0.1 mL OR 1–2 drops |
| Light infestation | 2.5–5 mL as a root drench |
| Heavy infestation | 10–20 mL for the initial root drench |
Mix it into the water and apply it as a root drench, the same way in coco, soil or any other medium. The heavy rate is a first drench to knock a bad problem down, not a dose for every watering. Keep prevention and treatment separate.
Keep it away from sterilizers
BMC is biological. Bleach, HOCl and other sterilizers work against it, so they don't go in the same water.
- In a sterile program (bleach in every reservoir): BMC is a temporary fix. Leave the sterilizer out while you treat the gnats, then go back to your normal bleach routine once the problem is solved.
- In soil, other non-sterile systems or with CropSalt Granular: there's no bleach in the program anyway, so BMC can stay in as ongoing prevention at 0.1 mL per gallon OR 1–2 drops per gallon.
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