I have an old brick bungalow built in 1939. The drain line in the bathroom is clogged. The tub drains extremely slowly and when we run water in the sink brown water bubbles up into the tub - which then takes quite a while to drain. There's no problem at all with or from the toilet.
The only thing I can think of that should be plugging the drain up would be hair - 3 women showering, 1 short-haired dog getting bathed.
I've used DrainPro gel 3 times in the bathtub drain trying to open it up but no success; I can't even tell I've done anything. I'm concerned about using anything too strong because of the age of the pipes - I don't want to burn through them and cause a greater problem.
I am hoping to avoid the expense of having a plumber come out to open up the drain but I need help quickly. Any suggestions/ideas?