Poly[aqua-(μ(11)-4,6-dihy-droxy-benzene-1,3-disulfonato)-dipotassium].

In the title salt, [K2(C6H4O8S2)(H2O)]n, both K+ ions exhibit a seven-coordination with K—O bond lengths in the range 2.6600 (14) to 3.0522 (16) A. One K+ ion is coordinated by seven O atoms from the sulfonate and phenolic hy­droxy groups of six 4,6-dihy­droxy­benzene-1,3-disulfonate (L 2−) anions while the other K+ ion is coordinated by six O atoms from the sulfonate and phenolic hy­droxy groups of five L 2− anions and one water O atom. The L 2− anion exhibits chelating–bridging multidentate coordination to potassium, resulting in the formation of a cross-linked three-dimensional network.