We use nematodes, they will eat eggs but once you have an infestation I'm not sure how effective they will be. They do completely eliminate fungus gnats though, but not if you miss a pot!

Root Aphids are not native to CO so you won't track them in from outside, vectors of contamination are usually potting soil, although I know some guys that just got them in their hydro system, new hydroton is the only way we think they got in...