Thanks for clarifying this ...Its just a fixed percentage per day. A hold over from ETO, we do have to look into it as being a plumber's son I know its stupid that its always breaking.
at least it helps me with using a little bit less dishwashing detergent (by washing dishes only when I have used around 5 plates)
(my false belief that it might influence the probability for the sink breaking put a certain restraint on this before)