I live in a 6th floor of an old building with piping that clogs easily and frequently. We have to fix that, but it's expensive so we have to find temporary alternatives in the meantime.
Our washing machine has a drain hose that dumps the soapy water to a sink. The water coming out of the hose doesn't have suds, but as soon as it hits the sink, you can see the top layer of suds being formed. Our neighbor in the 1st floor sees these suds coming out of their dishwasher and rightfully complains.
On the other hand, to make sure it was the soap, we tested by filling the sink with plain water so it goes down the drain. The neighbor didn't see anything in her sink.
I know I can use less soap, but it will still make suds.
My question: what can I do to minimize the suds that go through the drain pipe? The ideal solution would be that the water in the sink does not have suds, so the water that goes down the drain does not have suds either.
Also, I just read that vinegar can reduce suds. But my concern is that the vinegar will reduce suds inside the washing machine and not the suds buildup in the sink when washing machine is rinsing.