After having to cut one of the lines on my Sundance Spa I noticed that the inside of the flex Pipe is crumbling. Can anyone tell me if this is from old age, chemicals or Freezing? Should I replace all of the lines. Will this crumbling effect the proformance of the tub. The tub is a 1991 any help would be appreciated Paul

might be hard water build up. your flex should be ok

I have had tubs with much older lines than that, some have froze, none have had crumbling. I would suspect chemical reactions.