My gnats were driving me crazy for a while, and eating the roots of my seedlings. I tried the mosquito bits, but what really worked for me was Gnatrol. It's got the same active ingredient as mosquito bits, live
bacillus thurigensis (BT). It's a beneficial bacteria that give the gnat larvae indigestion so they can't eat or grow up to be gnats. The Gnatrol has a lot more of the
BT than mosquito bits. The smallest package is a lifetime supply for a home-grower. I used 1 teaspoon per gallon of my regular feed, mixed in warm water the day before, so the bacteria can multiply (feeding on my nutes I guess). By the next day my nutes turned cloudy with
bacillus thurigensis. If I'm watering multiple gallons, I use the Gnatrol gallon last, so one gallon is enough for several plants. Do it again the following week after any eggs have hatched. My gnats disappeared on day 1, but I did the followup 7 days later, and again any time I see a gnat. I did some research on brewing your own
bacillus thurigensis. Their favorite temperature is around 98°F. I treat them like yeast, and make sure my nutes are below 100° or 110°F when I put the Gnatrol in there, to avoid killing those magical bacteria.
listed by the Organic Materials Review Institute (OMRI) for use in organic production. Expiration date: July 31st 2027 Bacillus thuringiensis, subsp. israelensis, strain AM 65-52fermentation solids, spores and insecticidal toxins . . . . . 37.4%Other Ingredients . . . . . . . . . . . . . . . . ...
www.organicbti.com