Question: Ed, I have recently found a solution to my gnat problem in GoGnats, an organic additive that goes into the nutrient water, which was recommended by my hydroponic guy. It smells like cedar and they (the gnats) look dead now. I would still like to know if they cause serious root damage as most books don’t list them as a problem.
Ed’s Rosenthal: Fungus gnats do cause serious damage because they feed in part on the roots, opening them up to infection. In addition they are vectors for diseases.