I have a several plants in my house and for the past couple of years I have struggled with a gnat like fly. I believe it lives of the fungus in the dirt. I have tried every kind of plant spray and nothing kills them they really don’t hurt my plants at all they are just very irritating. I did go to a nursery and they suggested layering all my plants with about 2 inches of sand. Do you have any other suggestions?

Thank you,

Chantelle