I have several houseplants and we seem to have a massive outbreak of fungus gnats all of a sudden. I do allow my plants to dry out and remain so for several days before watering again. I check the moisture levels with a meter to be sure that I am not over watering. I do not want to have to purchase any chemical or bacterial insecticide. (I am a college student and don’t seem to have a dime to spare at the moment.) What can I do to eliminate the fungus gnats and larvae efficiently?
I do not want to throw my plants away. As I said, I don’t have a lot of money, and I can’t afford to replace them. Some of them also have sentimental value to them.

Unfortunately, the gnats are in the soil. You can try a soapy solution next time you water. Add some dishwashing soap to the water. It’s not a guarantee, but it’s worked for me before. The gnats eggs were laying dormant in the potting soil, they are now hatching. I’ve given up on trying to fight the little boogers == whenever I see them now — I toss the plant out and buy new ones from a different store.