We recently got an R/O system and wanted it in the basement since we dont have room under our sink for it. It's close to the fridge just upstairs. The problem is we don't have a place to drain. The only drain pipe nearby is the main drain for the house to the city hookup. As a temp solution we are draining to a kitchen drain pipe up in the ceiling but the system makes so much noise (thumping) when its running I'm assuming because it needs to pump the drainage upward instead of it flowing downwards. My question is, what's the best way to drain this in this situation? Can I connect to the main house drain pipe shown in the picture below? Not sure it is allowed or a good idea. Thanks for any recommendations here.