In our master bath, after taking a bath, the water drained but the strange thing was that the water in the toilet bubbled and drained from the bowl. After that I put some virgin sulfuric acid down the tub drain as well as the bowl hoping that this would remove any organic clog that may be occurring. After letting the acid sit for about 30 minutes and then flushing it with water I figured all was fine. That was until this evening when I went to use the restroom and stepped in a puddle of water. Upon turning on the light I find a tub filled with brown water and a toilet with brown residue on the bottom. Any ideas as to what may be going on?

Is this a house, apartment or a condo that you live in? The toilet draining indicates a vent problem but the sewage in your tub and toilet sounds like a clog downstream from the fixtures. Anyone living over you? Back to you, Tom

This is a house. It was built in 1975 and does do appear to have a clear out on the outside of the house.

"virgin sulfuric acid " you are going to hurt yourself or at least your pipes. Do not use this stuff any more. Is this a one or two story home and what level is the master? Tom will do the rest Thursday morning. I'm sleepy and won't be here much longer.