Well after several years of just letting the grey water drip onto the ground after exiting the tank through a simple tube and no grease trap there is no residue on the ground, just grass and rhododendrons close. I don't run much water into the tank, just one person. Never poor cooking grease into a septic tank. How ever I do smell methane after taking a shower. If I live long enough I will put a charcoal filter on the top vent.
I still want swamp cabbage with lots of roots to collect phosphates. Not that I would recognize symptoms....are there any to look for??
I just got a horse radish root free at the food bank, maybe that would be a good filter plant???