It dissolves the accumulations formed in the filters. Does not damage surfaces. It is concentrated, provides economical use. Over time, residues such as body oil and sun oil accumulate in the filters of heavily used pools and form a waterproof film layer. In addition, the lime contained in the water accumulates between the sand particles, blocking the sand and rendering it inoperable. Calcex Fitler; It cleans such dirt and lime formations in the pool and filter without damaging the material. It does not contain hydrochloric acid. It should only be used for the purposes stated on the label.