The water in my tap is awful. It is very hard, causes a terrible stone. While the kettle can be descaled with vinegar or another product intended for this, it is not so easy with a washing machine. Some time ago I bought a Domol liquid that is supposed to soften the water. I don't want to change the washing machine next year, because the water in Gdańsk is very hard.
Price: I bought for PLN 6, but I don't know what the daily price is;)
A few words from the producer: ,,Domol water softening gel dissolves in the full temperature range and prevents scale build-up. The stone-covered heater heats up much longer, so thanks to the Domol softening gel you save not only energy and time, but also the amount of detergent needed for washing. "
As I mentioned at the beginning - the water level in my tap calls for vengeance to heaven in terms of hardness. I even checked it out of curiosity when we got a water hardness tester with the dishwasher. It turned out that the water is hard. To be honest, the result didn't surprise me ...
For washing, I add 1 liquid cap (pour into the same hole where I put the washing powder). Recently I saw a water softener in Rossman powder for 9,99 PLN. I wonder if it's as good as the liquid one.