The drain from the tub upstairs has been slow for years. I figured itís a 20 year old house, and itís a tub thatís not used very often. I have poured gallons of every kind of drain opening solvent I could find down it, and nothing seems to help. Last week it finally closed shut. Nothing was getting through. I went out and got a 50í snake. My 25í snake just could not get to the clog. I pushed my snake in and hit something solid. I figured it had to be a ĎTí and I just could not make the turn. Down I went to the basement. Found a sharp 90, and decided I would cut it out and replace it with a sweep. When I cut the pipe, there was clog of gunk, a clay like substance that had settled and clogged the entire pipe. I ended up replacing about 3í piece of pipe that was full of the stuff. It seemed almost like it was soap that had reformed in the pipe. It was solid, nothing was getting through. What was it? Could it be in my other pipes? How do I get rid of the stuff without having to replace the entire drain structure of the house? So far no other drains appear to be slow. Crossing my fingers???