Well, the bug problem got a lot less when I put DE on top of all of them. Interesting enough, I read a thread on another forum where a guys 40 pot RDWC grow got completely devastated by fungus knats. The knats got out of control, which led to stress and lots of tissue damage, then he got a wilting virus. Game over.
It's a whole different game when your growing large scale. Not that I'm commercial scale or anything but if I lost a crop in the last couple weeks I would eat about $1500 in electricity and nutrients. A $10 bag of DE will prevent ANY bugs in your containers...pretty cheap investment