The jars containing tablets with the poison (not the organisms) of bacillus thuringensis. I have every now and then thrown over six months a tablet into the feeding water and controls the success with yellow panels. Initially, the population decreases rapidly and remains for about 2 months in a very small level. Then slowly disappear the last fungus gnats and you can adjust the Behandlkung.
But this time you should plan. As the population otherwise spreads again.
