@Frogster - regarding 4C-Field from C-No Insects. This looks VERY interesting. I've been fighting gnats for a couple of months -- trying everything in the book, but with minimal success so far. The company appears to be in Holland with product availability in UK. Unfortunately for me, I'm in USA and don't see a source here yet. Will be interested in following along if you post up any experience with this .... they say 72 hours for results