Proportional polyphosphates dosing system for anti-scale and anticorrosive treatment of all designed systems for the production of hot sanitary water for domestic use. DOSPRO Hydrodynamic proportional polyphosphates dosing system operation exploits the depression produced by the water that flows through the cartridge, guaranteeing the aspiration of the solution with a polyphosphates base. A special labyrinth disk (exclusive patented system), guarantees the correct dosage also with variable water flow respecting the current Regulations. DOSPRO Hydrodynamic proportional polyphosphates dosing system is equipped with a floating red ball that, once it reaches the bottom of the bowl, it will indicate the solution depletion and, consequently it refills with two new tabs. The cartridge consumption is proportional to the water consumption. The autonomy 26-27 m3 is indicative and influenced by the temperature, frequency of use and by the sampling frequency. DOSTABS refills blister contains 6 tabs. Suitable for being installed on wall-mounted boilers, boilers, water heaters, also in presence of small dimensions, for an efficient treatment against limestone and corrosion.