What type of pests do you have. I had a gnat problem for a while. I tried a bunch of things. The last thing I have done was put half-inch layer of sand on the top of my soil. Since a few weeks ago doing it, my gnat problem is just close to being solved. I very seldom see a gnat anywhere.
So in the ongoing war I have had with gnats, they are currently losing their campaign on "Pelt Hill."