When I run my bathroom sink, water backs up in y bathtub. Lately, that water is black. I've tried Drano. idea?
We have "snaked" the drain and used many bottles of Liquid Plumr and Drano, but the bathtub drains very slowly still and gets backed up when I run the water in the sink. The reverse, however, does not apply. The sink drains just fine and doesn’t get backed up.