In the title compound, [Ca(C(15)H(9)O(7)S)(H(2)O)(6)](C(15)H(9)O(7)S)·3H(2)O, the Ca centre has a distorted deca-hedral geometry, coordinated by six O atoms from water mol-ecules and one sulfonate O atom. The crystal structure is stabilized by aromatic π-π inter-actions, with centroid-centroid distances of 3.765 (5) and 3.896 (5) Å between the phenyl ring and the benzene ring of the chromene un...