Laundry washing machine comprising a water softening device

A laundry washing machine (1) comprising an outer casing (2) and, inside said outer casing (2), a washing tub (3), a rotatable drum housed in axially rotatable manner inside the washing tub (3) and structured for housing the laundry to be washed, a detergent dispenser (10) which is structured for supplying detergent into the washing tub (3), a fresh-water supply circuit (12) which is structured for selectively channelling a flow of fresh water from the water mains towards the detergent dispenser (10) and/or the washing tub (3), and an internal water softening device (13) filled with a water softening agent capable of reducing the hardness degree of the fresh water directed towards the detergent dispenser (10) or the washing tub (3); the laundry washing machine (1) furthermore comprising: a regeneration-agent reservoir (21) located/recessed inside the outer casing (2) and structured for being manually fillable with a given amount of consumable salt or other regeneration agent; a first water-supply line (19) which is structured for selectively channelling a flow of fresh water into said regeneration-agent reservoir (21) so as to form some brine; a brine reservoir (45) which is fluidically connected to said regeneration-agent reservoir (21) for receiving and accumulating the brine arriving from said regeneration-agent reservoir (21); and a detector assembly (55) which is capable of detecting when the salinity degree of the brine stored into brine reservoir (45) exceeds a predetermined minimum salinity value.