Because our water is too hard, and we use an ion exchanger, no tap water for the aquarium can be used. Thus I am forced by osmosis and the appropriate preparation to adjust the water. The product is so far very good. I always solve it in a sip of mineral water in front before I give it in the provided means of osmosis water.
One star deduction I forgive because of the price and also because apparently the packaging design has been changed. The now delivered jar is indeed slimmer but it also significantly higher and no longer fits in my shelf.