You are truly insane! Way to go! Who woulda thunk it? Too bad you posted your idea B4 applying for patent. Perhaps the addition of a battery, pump, or siphon powered gravel vacuum with filter bag at the trimmer would help with trimmings? Those are basically small shop vacs anyway.
Use a fine mesh net to skim the trimmings from the surface, move it in figure 8 pattern it pulls trimmings toward intersection of 8, like collecting daphnia from a pond. Or attach a U shape tube on a gravel vac and suck the trimmings from just below surface. Or similar U tube on inlet of hanging filter.
Hmmmm, wonder if I can apply for patent online? I'm gonna be rich. RICH! I tell ya!
After posting I saw that MMantelli done solved the trimming problem. That'll teach me to look for page two B4 posting. I'd best keep my day job. Looks like I'm still not gonna be rich.