Take me to your leader!
The water in Düsseldorf is very hard; this is great for beer, but shit for tea! For years I’ve had to use a water filter, this is okay but is inconsistent and takes a while to work out how often to change the filter - I ended up buying a pH meter for greater accuracy - but now we have a dedicated water softener. Not only is tea consistently better, we don’t need any protection against calcium in the washing machine, dishwasher and no calcium spots. The device wasn’t cheap but it should be a lot cheaper to run than all the various tabs, etc. Well, that’s the theory!