These are the two numbers you need. German degrees is the same as dH and mg/l CaCO3 is the same as ppm. Fish profiles use either dH or ppm, and you now have your hardness in both - 253 ppm and 15 dH.Total hardness 253 mg/ I CaCO3
15 degrees German
(The reason I have a reputation for understanding water chemistry is that I have a degree in chemistry, although it was a long time ago now. And my son also has a degree and doctorate in chemistry and used to work as an analyst for a water testing company so I can always ask him )