So i made a remedy i found in youtube plus added one more ingredient, goes as follows, 16 ounce hydrogen peroxide, 2 tbs of hot sauce, 2 tbs of dish soap non antibacterial, cooking oil about 2 tbs 1 tbs white vinegar all in one gallon. flood the pots and keep humidty down until next feeding, since it can create mold if humidty too high.
Vegetation, 6 weeks
Rosetta Stone, (hybrid) from Grimms Brothers (Seedsherenow.com)
In had the same issue. I left the soil to dry out until the top 2 inches were bone dry (3-4 day wait) and then i watered my plant with 1 part hydrogen peroxide 3% to 4 parts water and it worked out for a while. Fungus gnats tend to thrive in moist areas so you might be overwatering your plants.
i water them once a week but for some reason it stood moist, so what i did was that and now just gonna let it dry out all the way until the leaves weep a bit, and for the next plants will tend to add more perlite into the soil since it has only what happy frog brings in,