Hey All, so I am having issues with my basement sink. The sink backs up when I let the water run for about 10 seconds. The drain links to my sump pump via about 4 feet of plastic piping. So I thought naturally it was just a clog somewhere in the pipes. Tried Drano and no progress. I decided to take the pipes off and manually get any sludge build up that might have been in there. Only thing is, when I looked in the removed pipes, there was no blockage. Far as I can tell, the pipes are clean. The sump pump does work, I can hear it every so often during the day. When I turn the water on in the sink and then turn it off, I can hear a faint trickling sound, very similar to what you would hear if water was getting by some clog slowly. Anyone have any ideas what could be the problem? I see there's a place on the sump pump for the filter, I was thinking of opening it up to see if there's anything weird going on in there, because I'm basically out of ideas, as a newbie first time home owner. Thanks very much for any suggestions!