Can anyone help me? I can access the drain and vent inside the wall (to the adjacent bathroom), but not sure whether I should put in a standpipe or just drain it directly to the main drain. I'm sure purist here will say to install a new standpipe and properly vent it, but wondering if I really need to do all of this. If I went the standpipe/vent route, how much of that can stay inside the wall and how much can be exposed. Anyone got any good pictures of a standpipe install for a softener/filter? I really just want a professional looking solution done right. It's in a drywalled garage, so I want to keep it neat. I thought of putting in a washer utility box to keep it all inside the wall, but maybe this isn't necessary. If someone's done this before and can share their experience, I would surely appreciate it.