I've been using a teaspoon per Gallon of Gnatrol (BT culture) at the first sign of a gnat. I mix it in my nutes the night before I use it. You can tell the BT bacillus is growing in there because the nutes get more cloudy overnight. I read somewhere that the ideal temperature for BT propagation is in the 90's (°F). It shuts the gnats down right away. Another application after 5 days gets any larvae that hatch later, before they can mature and lay more eggs. I tried "mosquito bits" before, but didn't have much success with it, had to apply multiple times. Gnatrol has much more live BT, and no chunks of vermiculite or whatever that is in the mosquito bits that plug up every orifice. I think I got the 4 oz size of Gnatrol, and it might be a lifetime supply for my grow.@Hotfire are you using BAS living soil? I’m considering trying it on an autopot run since it’s water only. I hear fungus gnats are a problem but they sell some super strength BTI to help with that. Do you have any info or experience with either?
Gnatrol WDG Fungus Gnat Larvacide | organicbti.com
listed by the Organic Materials Review Institute (OMRI) for use in organic production. Expiration date: January 31st 2026 Bacillus thuringiensis, subsp. israelensis, strain AM 65-52fermentation solids, spores and insecticidal toxins . . . . . 37.4%Other Ingredients . . . . . . . . . . . . . . ...
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