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KRMosquito dunks are actually a really smart, low-toxicity way to deal with fungus gnats indoors—especially for seedlings and houseplants. I got mine on Amazon for around $20
🌱 What they are
Mosquito dunks contain a naturally occurring soil bacterium called Bacillus thuringiensis israelensis (usually shortened to BTI).
🦟 How they work:
BTI targets the larval stage, not the adult gnats.
1. Adult fungus gnats lay eggs in moist soil
2. Eggs hatch into larvae (tiny, translucent worms in the soil)
3. Larvae eat organic matter (and sometimes roots)
4. When they ingest BTI → it releases toxins in their gut
5. This kills the larvae before they can mature into adults
👉 No larvae = no new adults = population crash over time
🌼 Why they’re considered “organic” & safe
• BTI is naturally found in soil
• Only affects certain larvae (mosquitoes, fungus gnats, blackflies)
• Does NOT harm:
• plants 🌿
• people 👩🌾
• pets 🐾
• beneficial insects (like bees) 🐝
💧 How to use in an indoor grow setup
For fungus gnats, you don’t just drop the dunk in soil—you make a “tea”:
Option 1: Soak + water
• Break off a piece of dunk
• Let it sit in water for a few hours (or overnight)
• Use that water to irrigate your plants
Option 2: Crumble into watering can
• Crush a small piece
• Add directly to watering can
• Let it steep, then water
⏳ What to expect
• Works gradually (not instantly)
• You’ll still see adults for ~1–2 weeks
• Big improvement usually in 2–3 weeks
• Needs consistent use because new eggs keep hatching
⚠️ Important tips (this is where most people go wrong)
• Moisture matters → gnats thrive in wet soil
→ Let top layer dry slightly between watering
• BTI only kills larvae that eat it
→ You need to apply it regularly
• Combine with:
• Yellow sticky traps (catch adults)
• Bottom watering (reduces egg-laying on surface)
• Airflow (fan)
🌿 Note:
• BTI is safe for delicate seedlings
• Helps prevent root damage during early stages
• Especially useful in dense trays where limited airflow/lots of moisture = gnat heaven
#CombatFungusGnats #Seedlings #GrowersTips #FlowerFarming #kristasbloomsandblossoms
@kristasbloomsandblossoms
