I use castile soap as my wetting agent every watering and I use the dr bronners peppermint stuff at that and it has pest killing properties as well! Especially fungus gnats it’s kills larvae on contact so didn’t have any show up this run! Got some other creatures crawling in my soil but runs almost done so gonna water in some spinosad next feed so it’ll actually kill off whatever invaders I have! Then I’ll add beneficial bugs before next run!
But no straw doesn’t help against fungus gnats! It helps keep soil moist up top so if u have them it’ll actually make them worse most likely!