Question:
The rim of my toilet bowl builds up with black gunk. I clean it often but the gunk returns. Can this be solved by replacing the toilet or is there a pipe problem?
Answer:
You have a mineral build up in the toilet caused by hard water. Try pouring CLR down the flush valve, (which is the white plastic tube about 1″ in diameter that the flapper sits on). Allow the CLR to sit in the tank overnight and flush the tank in the morning to clear out the chemical. This will help to dissolve the build-up. A new toilet will also solve the problem until minerals build up over a few years.