Yeah, I'd have a heavy, filter system before it enters tank (especially from a river/lake). Then another filter to the drinking water source on the sink and could then use another filter like a Berkey, countertop type filter, since those filters filter the best out of em all. Maybe even reverse osmosis/UV filter system and plumb waste RO water back into fresh thru mineral filter of sorts. Idk, typing out loud.
Good points on all the solids in grey tank. Best way to get rid of all that? Obviously, reduce putting solids down drain, but then what? Maybe a heating element that burns off grey water and a removable grey water filter of sorts to pull out all the solid/unburnt material? Definitely adds complexity, loving the problem solving help here. I love this s#!t.