To soak dirty, greasy and smelly laundry before washing
To soften the water - adding washing soda to the washing machine (add to the washing powder container) will soften the water and thereby protect the heating element and other parts of the washing machine from limescale.
Thanks to the fact that it softens water, it increases the efficiency of (not only) ecological washing powders and gels, it is therefore possible to reduce the dosage of detergents.